// orchestra-worker consumes router-issued leases for one or more local
// execution backends. Each declared harness is a separate federation identity
// with its own token, cursor, backend, and state file, because the coordinator
// authorizes a lease call by comparing the URL's worker id against the lease's
// harness id. Homesrv remains the scheduler and CAS authority. This process
// owns only local Git and pane operations.
package main

import (
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"log"
	"net/http"
	"orchestra/internal/agentctx"
	"orchestra/internal/buildinfo"
	"orchestra/internal/continuity"
	"orchestra/internal/domain"
	"orchestra/internal/federation"
	"orchestra/internal/herdr"
	"orchestra/internal/orchestrator"
	"orchestra/internal/review"
	"orchestra/internal/workphase"
	"os"
	"os/exec"
	"os/signal"
	"path/filepath"
	"reflect"
	"sort"
	"strconv"
	"strings"
	"syscall"
	"time"
)

type worker struct {
	api     federation.Client
	backend herdr.Backend
	// herdr is retained as a test/backward-compatibility alias. Production
	// workers set backend; executionBackend keeps older state-machine tests
	// from needing protocol-irrelevant rewrites.
	herdr                                  *herdr.Client
	harnessID, harness, repo, root, remote string
	projects                               map[string]projectConfig
	cursor                                 uint64
	tasks                                  map[string]domain.Task
	sessions                               map[string]herdr.Session
	leases                                 map[string]lease
	releases                               map[string]releaseTransaction
	quarantined                            map[string]bool
	statePath                              string
	hard                                   float64
	registration                           federation.Worker
	lastError                              string
	lastErrorAt                            time.Time
	soft                                   float64
	window                                 int64
}

func (w *worker) executionBackend() herdr.Backend {
	if w.backend != nil {
		return w.backend
	}
	if w.herdr != nil {
		return w.herdr
	}
	return nil
}

func (w *worker) recordError(err error) {
	if err == nil {
		return
	}
	w.lastError = err.Error()
	w.lastErrorAt = time.Now().UTC()
}

func (w *worker) health(ctx context.Context) federation.WorkerHealth {
	h := federation.WorkerHealth{HerdrStatus: "unknown"}
	if backend := w.executionBackend(); backend != nil {
		h.Backend = backend.Kind()
	}
	for taskID, session := range w.sessions {
		// Workers currently advertise capacity one. Pick deterministically so a
		// recovered legacy state with more sessions remains intelligible.
		if h.ActiveTask == "" || taskID < h.ActiveTask {
			h.ActiveTask, h.ActivePane = taskID, session.PaneID
		}
	}
	if backend := w.executionBackend(); backend != nil {
		checkCtx, cancel := context.WithTimeout(ctx, 3*time.Second)
		err := backend.Check(checkCtx)
		cancel()
		h.CheckedAt = time.Now().UTC()
		if err == nil {
			h.HerdrStatus = "reachable"
		} else {
			h.HerdrStatus = "unreachable"
			w.recordError(fmt.Errorf("local %s backend: %w", backend.Kind(), err))
		}
	}
	h.LastError, h.ErrorAt = w.lastError, w.lastErrorAt
	return h
}

type lease struct {
	Epoch              string    `json:"epoch"`
	HandoffRef         string    `json:"handoff_ref,omitempty"`
	TransactionID      string    `json:"transaction_id,omitempty"`
	AnchorSHA          string    `json:"anchor_sha,omitempty"`
	PickupAcknowledged bool      `json:"pickup_acknowledged,omitempty"`
	Version            int       `json:"version"`
	Until              time.Time `json:"until"`
	UsageBaseline      float64   `json:"usage_baseline,omitempty"`
	// ProgressSHA hashes the pane capture taken at the last renewal. Renewal
	// requires the pane to have changed since then, or the agent to be busy.
	ProgressSHA string `json:"progress_sha,omitempty"`
}
type releaseTransaction struct {
	ID            string    `json:"id"`
	LeaseVersion  int       `json:"lease_version"`
	Ref           string    `json:"handoff_ref,omitempty"`
	AnchorSHA     string    `json:"anchor_sha,omitempty"`
	Phase         string    `json:"phase"` // prepared, anchor_pushed, event_committed, pickup_validated, predecessor_retired
	AgentReleased bool      `json:"agent_released,omitempty"`
	LastError     string    `json:"last_error,omitempty"`
	UpdatedAt     time.Time `json:"updated_at"`
}
type projectConfig struct {
	Repo           string   `json:"repo"`
	Root           string   `json:"worktree_root"`
	Remote         string   `json:"remote"`
	QualityGate    string   `json:"quality_gate,omitempty"`
	SafeOperations []string `json:"safe_operations,omitempty"`
}
type completionEvidence struct {
	TaskID      string    `json:"task_id"`
	Project     string    `json:"project"`
	Worker      string    `json:"worker"`
	Harness     string    `json:"harness"`
	PaneID      string    `json:"pane_id"`
	BaseSHA     string    `json:"base_sha"`
	ResultSHA   string    `json:"result_sha"`
	Branch      string    `json:"branch"`
	Remote      string    `json:"remote"`
	QualityGate string    `json:"quality_gate,omitempty"`
	GateExit    int       `json:"gate_exit"`
	GateOutput  string    `json:"gate_output,omitempty"`
	CompletedAt time.Time `json:"completed_at"`
}

// tail keeps the end of a gate log, which is where the failure is.
func tail(s string, max int) string {
	if len(s) <= max {
		return s
	}
	return s[len(s)-max:]
}
type workerState struct {
	Cursor      uint64                        `json:"cursor"`
	Sessions    map[string]herdr.Session      `json:"sessions"`
	Tasks       map[string]domain.Task        `json:"tasks"`
	Leases      map[string]lease              `json:"leases"`
	Releases    map[string]releaseTransaction `json:"releases"`
	Quarantined map[string]bool               `json:"quarantined,omitempty"`
}

func (w *worker) load() error {
	b, e := os.ReadFile(w.statePath)
	if e == nil {
		var s workerState
		if err := json.Unmarshal(b, &s); err != nil {
			return fmt.Errorf("corrupt worker state %s: %w", w.statePath, err)
		}
		w.cursor = s.Cursor
		w.sessions = s.Sessions
		w.tasks = s.Tasks
		w.leases = s.Leases
		w.releases = s.Releases
		w.quarantined = s.Quarantined
	} else if !errors.Is(e, os.ErrNotExist) {
		return fmt.Errorf("read worker state %s: %w", w.statePath, e)
	}
	if w.sessions == nil {
		w.sessions = map[string]herdr.Session{}
	}
	if w.tasks == nil {
		w.tasks = map[string]domain.Task{}
	}
	if w.leases == nil {
		w.leases = map[string]lease{}
	}
	if w.releases == nil {
		w.releases = map[string]releaseTransaction{}
	}
	if w.quarantined == nil {
		w.quarantined = map[string]bool{}
	}
	return nil
}
func (w *worker) save() error {
	b, e := json.Marshal(workerState{Cursor: w.cursor, Sessions: w.sessions, Tasks: w.tasks, Leases: w.leases, Releases: w.releases, Quarantined: w.quarantined})
	if e != nil {
		return e
	}
	if e := os.MkdirAll(filepath.Dir(w.statePath), 0700); e != nil {
		return e
	}
	tmp := w.statePath + ".tmp"
	f, e := os.OpenFile(tmp, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0600)
	if e != nil {
		return e
	}
	if _, e = f.Write(b); e == nil {
		e = f.Sync()
	}
	if closeErr := f.Close(); e == nil {
		e = closeErr
	}
	if e != nil {
		_ = os.Remove(tmp)
		return e
	}
	if e = os.Rename(tmp, w.statePath); e != nil {
		return e
	}
	dir, e := os.Open(filepath.Dir(w.statePath))
	if e != nil {
		return e
	}
	defer dir.Close()
	return dir.Sync()
}

// quarantine stops a pane before its lost lease mapping can be forgotten.
// A failed close remains durable and is retried; it is never treated as a
// harmless cleanup error while the old harness could still be working.
func (w *worker) quarantine(ctx context.Context, taskID string, s herdr.Session) {
	if w.executionBackend() == nil {
		w.quarantined[taskID] = true
		return
	}
	if err := (herdr.CLIAdapter{Backend: w.executionBackend(), Harness: w.harness}).Kill(ctx, s); err != nil {
		w.quarantined[taskID] = true
		w.recordError(fmt.Errorf("quarantine %s: %w", taskID, err))
		return
	}
	delete(w.sessions, taskID)
	delete(w.quarantined, taskID)
}

func (w *worker) retryQuarantines(ctx context.Context) {
	for taskID := range w.quarantined {
		if s, ok := w.sessions[taskID]; ok {
			w.quarantine(ctx, taskID, s)
		}
	}
}

type artifactCAS struct{ api federation.Client }

func (c artifactCAS) PutArtifact(b []byte) (string, error) {
	return c.api.PutArtifact(context.Background(), b)
}
func (c artifactCAS) Artifact(ref string) ([]byte, error) {
	return c.api.Artifact(context.Background(), ref)
}

func created(e domain.Event) (domain.Task, bool) {
	if e.Type != "TaskCreated" {
		return domain.Task{}, false
	}
	var p struct {
		Source      string   `json:"source"`
		ExternalID  string   `json:"external_id"`
		Project     string   `json:"project"`
		Capability  []string `json:"capability"`
		Title       string   `json:"title"`
		Description string   `json:"description"`
		Acceptance  []string `json:"acceptance"`
		QualityGate string   `json:"quality_gate"`
	}
	if json.Unmarshal(e.Payload, &p) != nil || p.Source == "" || p.ExternalID == "" || p.Project == "" {
		return domain.Task{}, false
	}
	return domain.Task{ID: e.TaskID, Source: p.Source, ExternalID: p.ExternalID, Project: p.Project, Capability: p.Capability, Title: p.Title, Description: p.Description, Acceptance: p.Acceptance, QualityGate: p.QualityGate}, true
}

func (w *worker) project(t domain.Task) (projectConfig, error) {
	if w.projects != nil {
		if p, ok := w.projects[t.Project]; ok && p.Repo != "" && p.Root != "" && p.Remote != "" {
			return p, nil
		}
		return projectConfig{}, fmt.Errorf("project %q is not configured on worker", t.Project)
	}
	return projectConfig{Repo: w.repo, Root: w.root, Remote: w.remote}, nil
}

func (w *worker) syncBase(ctx context.Context, p projectConfig) error {
	if out, err := exec.CommandContext(ctx, "git", "-C", p.Repo, "fetch", p.Remote, "--prune").CombinedOutput(); err != nil {
		return fmt.Errorf("fetch base checkout: %s: %w", out, err)
	}
	branch, err := exec.CommandContext(ctx, "git", "-C", p.Repo, "symbolic-ref", "--quiet", "--short", "HEAD").Output()
	if err != nil {
		return fmt.Errorf("identify base branch: %w", err)
	}
	branchName := strings.TrimSpace(string(branch))
	if out, err := exec.CommandContext(ctx, "git", "-C", p.Repo, "merge", "--ff-only", p.Remote+"/"+branchName).CombinedOutput(); err != nil {
		return fmt.Errorf("fast-forward base checkout: %s: %w", out, err)
	}
	return nil
}

func (w *worker) start(ctx context.Context, t domain.Task, ref string) error {
	var wt string
	var h continuity.Handoff
	var err error
	p, err := w.project(t)
	if err != nil {
		return err
	}
	// Synchronize the local base before any worktree operation. A worker never
	// treats a coordinator-side path as truth; the Git remote is the only
	// cross-machine transport.
	if err := w.syncBase(ctx, p); err != nil {
		return err
	}
	if ref != "" {
		b, err := w.api.Artifact(ctx, ref)
		if err != nil {
			return err
		}
		h, err = continuity.Decode(b)
		if err != nil {
			return err
		}
		if out, err := exec.CommandContext(ctx, "git", "-C", p.Repo, "fetch", p.Remote, "--prune").CombinedOutput(); err != nil {
			return fmt.Errorf("fetch pickup anchor: %s: %w", out, err)
		}
		wt = filepath.Join(p.Root, t.ID)
		if _, err := os.Stat(wt); os.IsNotExist(err) {
			if out, err := exec.CommandContext(ctx, "git", "-C", p.Repo, "worktree", "add", "-b", "orchestra/"+t.ID, wt, h.Anchor.GitSHA).CombinedOutput(); err != nil {
				return fmt.Errorf("create pickup worktree: %s: %w", out, err)
			}
		}
		if err = continuity.ValidatePickup(wt, h, taskHash(t)); err != nil {
			return err
		}
	} else {
		wt, err = (orchestrator.GitWorktrees{Repo: p.Repo, Root: p.Root}).Create(ctx, t)
		if err != nil {
			return err
		}
	}
	backend := w.executionBackend()
	if backend == nil {
		return fmt.Errorf("execution backend is not configured")
	}
	if _, err = backend.Worktree(ctx, p.Repo, wt, "orchestra/"+t.ID); err != nil {
		return err
	}
	s, err := backend.StartAgent(ctx, wt, wt, "orchestra/"+t.ID, w.harness, t.ID)
	if err != nil {
		return err
	}
	// The phase this session was launched to run. A later phase change makes
	// this session's context the wrong one, which is what rotates it (F22).
	s.Phase = string(currentPhase(t))
	s.TaskFileSHA = taskHash(t)
	if w.harness == "claude" {
		s.ContextHandoffSHA, _ = fileSHA256(filepath.Join(wt, "HANDOFF.md"))
	}
	// One renderer, on both machines. The worker fetches the reduced
	// authority as data and renders it with agentctx, so a decision the human
	// recorded before this session existed is visible from its first turn.
	intent, err := w.api.Intent(ctx, t.ID)
	if err != nil {
		return fmt.Errorf("effective intent: %w", err)
	}
	in := agentctx.Input{
		Task: t, Intent: intent, Phase: t.WorkPhase, DecisionRequest: t.DecisionRequest,
		Git:       agentctx.GitState{Worktree: wt, Branch: "orchestra/" + t.ID},
		RepoRules: agentctx.DiscoverRepoRules(wt),
	}
	if sha, shaErr := herdr.HeadSHA(wt); shaErr == nil {
		in.Git.HeadSHA = sha
	}
	if ref != "" {
		in.Handoff = &h
	}
	if len(p.SafeOperations) > 0 {
		in.Policy = []string{
			"Permitted without an operator grant, inside this worktree only: " + strings.Join(p.SafeOperations, ", ") + ".",
			"Network access, secrets, destructive actions, and paths outside this worktree require an explicit operator approval.",
		}
	}
	if t.ResearchRef != "" {
		b, artErr := w.api.Artifact(ctx, t.ResearchRef)
		if artErr != nil {
			return fmt.Errorf("research artifact: %w", artErr)
		}
		r, decErr := workphase.DecodeStoredResearch(b)
		if decErr != nil {
			return fmt.Errorf("research artifact: %w", decErr)
		}
		in.Research = &r
	}
	if t.PlanRef != "" {
		b, artErr := w.api.Artifact(ctx, t.PlanRef)
		if artErr != nil {
			return fmt.Errorf("plan artifact: %w", artErr)
		}
		pl, decErr := workphase.DecodeStoredPlan(b)
		if decErr != nil {
			return fmt.Errorf("plan artifact: %w", decErr)
		}
		in.Plan = &pl
	}
	if t.Review != nil {
		b, artErr := w.api.Artifact(ctx, t.Review.ArtifactRef)
		if artErr != nil {
			return fmt.Errorf("review artifact: %w", artErr)
		}
		r, decErr := review.Decode(b)
		if decErr != nil {
			return fmt.Errorf("review artifact: %w", decErr)
		}
		in.Review = &r
	}
	built, err := agentctx.Build(in)
	if err != nil {
		return fmt.Errorf("build context: %w", err)
	}
	prompt := built.System + "\n\n" + built.Task
	// The transport decides what is submitted, never what the agent receives:
	// the file holds the exact bytes agentctx rendered either way.
	submitted, transport := prompt, herdr.LaunchInline
	if lt, ok := backend.(herdr.LaunchTransporter); ok {
		transport = lt.LaunchTransport(w.harness)
	}
	if transport == herdr.LaunchFileRef {
		submitted = herdr.LaunchReference
	}
	if writeErr := herdr.WriteLaunchContext(s.Worktree, prompt); writeErr != nil {
		// Under LaunchFileRef the file is the instruction, so a failed write
		// is a failed launch rather than lost evidence.
		if transport == herdr.LaunchFileRef {
			return fmt.Errorf("launch context %s: %w", t.ID, writeErr)
		}
		w.recordError(fmt.Errorf("launch context %s: %w", t.ID, writeErr))
	}
	// The launch instruction carried these, so the first turn boundary must
	// not re-announce them as news.
	for _, d := range intent.Decisions {
		s.DeliveredDecisions = append(s.DeliveredDecisions, d.ID)
	}
	w.sessions[t.ID] = s
	if err := w.save(); err != nil {
		return err
	}
	// A prompt response can be lost after the backend accepted it. Persist the
	// session first so the worker can reconcile/release it after restart.
	if err := backend.Prompt(ctx, s.PaneID, submitted, 0); err != nil {
		return err
	}
	// Acknowledging a launch means the harness accepted the instruction, not
	// that the adapter call returned nil. Without this the worker reported a
	// started agent while the prompt sat unsubmitted in the input editor.
	if c, ok := backend.(herdr.InputConfirmer); ok {
		evidence, confirmErr := c.ConfirmInput(ctx, s, submitted)
		if confirmErr != nil {
			// An unsubmitted prompt leaves a live pane that nothing owns, and
			// a retained session would make the retry skip this task
			// entirely. Reclaim both so the released lease can be re-leased.
			if killErr := backend.Kill(ctx, s); killErr != nil {
				w.recordError(fmt.Errorf("kill unlaunched pane %s: %w", t.ID, killErr))
			}
			delete(w.sessions, t.ID)
			if saveErr := w.save(); saveErr != nil {
				w.recordError(fmt.Errorf("save after failed launch %s: %w", t.ID, saveErr))
			}
			return fmt.Errorf("launch %s: %w", t.ID, confirmErr)
		}
		log.Printf("launch %s confirmed: %s", t.ID, evidence)
	}
	// Baseline the progress check at launch, not at the first renewal. The
	// renewal gate exempts a lease with no baseline, which handed a pane that
	// opened and never started a full free renewal period (F34) — the exact
	// case the gate exists to catch. Capturing here costs one pane read and
	// makes the first renewal a real comparison.
	if l, ok := w.leases[t.ID]; ok && l.ProgressSHA == "" {
		if text, progressErr := w.paneProgress(ctx, herdr.CLIAdapter{Backend: backend, Harness: w.harness}, s); progressErr == nil {
			l.ProgressSHA = domain.Hash([]byte(text))
			w.leases[t.ID] = l
		} else {
			w.recordError(fmt.Errorf("baseline launch progress %s: %w", t.ID, progressErr))
		}
	}
	if l, ok := w.leases[t.ID]; ok {
		if err := w.api.Start(ctx, t.ID, l.Epoch, l.Version, w.sessionEvidence(ctx, t.ID, s)); err != nil {
			return fmt.Errorf("ack start: %w", err)
		}
		l.Version++
		w.leases[t.ID] = l
		if err := w.save(); err != nil {
			return err
		}
	}
	if ref != "" {
		return w.ackPickup(ctx, t.ID, s)
	}
	return nil
}

func classifyLaunchError(err error, sessionStarted bool) string {
	// Positive evidence that the harness never accepted the prompt is not
	// uncertainty. Release the lease so the existing retry path can take it.
	if errors.Is(err, herdr.ErrPromptNotSubmitted) {
		return "prompt_not_submitted"
	}
	if sessionStarted {
		// A prompt response can be lost after herdr accepted it. Never reclaim
		// that pane just because its acknowledgement was uncertain.
		return "launch_uncertain"
	}
	text := strings.ToLower(err.Error())
	if strings.Contains(text, "handoff") || strings.Contains(text, "pickup") || strings.Contains(text, "task.md") {
		return "invalid_handoff"
	}
	return "launch_transient"
}

func taskHash(t domain.Task) string { b := continuity.RenderTaskFile(t); return domain.Hash(b) }

func fileSHA256(path string) (string, error) {
	b, err := os.ReadFile(path)
	if err != nil {
		return "", err
	}
	return domain.Hash(b), nil
}

func (w *worker) releaseReady(ctx context.Context) {
	for id, s := range w.sessions {
		if w.quarantined[id] {
			continue
		}
		if l := w.leases[id]; l.HandoffRef != "" && !l.PickupAcknowledged {
			if err := w.ackPickup(ctx, id, s); err != nil {
				w.recordError(err)
				continue
			}
		}
		if _, err := os.Stat(filepath.Join(s.Worktree, ".orchestra", "done")); err == nil {
			// A done marker is an intent, not enough on its own: do not race a
			// still-running native harness into committing half-written work.
			status, statusErr := (herdr.CLIAdapter{Backend: w.executionBackend(), Harness: w.harness}).AgentStatus(ctx, s)
			if statusErr != nil {
				w.recordError(fmt.Errorf("completion identity %s: %w", id, statusErr))
				continue
			}
			if herdr.IsBusy(status) {
				w.recordError(fmt.Errorf("completion %s deferred: agent status %s", id, status))
				continue
			}
			evidence, err := w.finalize(ctx, id, s)
			if err != nil {
				w.recordError(fmt.Errorf("complete %s: %w", id, err))
				log.Printf("complete %s: %v", id, err)
				continue
			}
			report, _ := json.Marshal(evidence)
			ref, err := w.api.PutArtifact(ctx, report)
			if err != nil {
				w.recordError(fmt.Errorf("upload completion %s: %w", id, err))
				log.Printf("upload completion %s: %v", id, err)
				continue
			}
			outcome, err := w.submit(ctx, id, s, evidence)
			if errors.Is(err, errReviewArtifact) {
				// Only the reviewing agent can fix this, and it is still alive
				// to be told. Dropping the done marker stops the five-second
				// retry and makes the corrected file the thing that finishes.
				w.recordError(fmt.Errorf("submit %s: %w", id, err))
				w.answerRefusedReview(ctx, id, s, err)
				continue
			}
			if err != nil {
				w.recordError(fmt.Errorf("submit %s: %w", id, err))
				log.Printf("submit %s: %v", id, err)
				continue
			}
			if outcome == federation.SubmitChangesRequested {
				// The sealed review sent the work back. The task is in
				// implement again, so the done marker is stale and the phase
				// change rotates this session on the next tick.
				_ = os.Remove(filepath.Join(s.Worktree, ".orchestra", "done"))
				log.Printf("review returned %s to implementation", id)
				continue
			}
			if outcome == federation.SubmitNoPublisher {
				if err = w.api.Complete(ctx, id, ref, evidence.ResultSHA, evidence.Branch, evidence.Remote, w.leases[id].Epoch, w.leases[id].Version, w.usageReceipt(s, w.leases[id]), w.sessionEvidence(ctx, id, s)); err != nil {
					w.recordError(fmt.Errorf("complete %s: %w", id, err))
					log.Printf("complete %s: %v", id, err)
					continue
				}
			}
			// Completion is durable before closing the exact pane. If close
			// fails, retain the session mapping for a later explicit cleanup.
			a := herdr.CLIAdapter{Backend: w.executionBackend(), Harness: w.harness}
			if err := a.Kill(ctx, s); err != nil {
				w.recordError(fmt.Errorf("close completed pane %s: %w", id, err))
				log.Printf("close completed pane %s: %v", id, err)
				continue
			}
			_ = os.Remove(filepath.Join(s.Worktree, ".orchestra", "done"))
			_ = os.Remove(filepath.Join(s.Worktree, ".orchestra"))
			delete(w.sessions, id)
			delete(w.leases, id)
			_ = w.save()
			continue
		}
		if _, err := os.Stat(filepath.Join(s.Worktree, herdr.HandoffReportFile)); err == nil || w.releases[id].ID != "" {
			w.advanceRelease(ctx, id, s)
			continue
		}
		w.rotationTick(ctx, id, s)
	}
}

func (w *worker) adapter(s herdr.Session, remote string) herdr.CLIAdapter {
	a := herdr.CLIAdapter{Backend: w.executionBackend(), Harness: w.harness, Window: w.window, CAS: artifactCAS{w.api}, Remote: remote}
	switch w.harness {
	case "claude":
		a.Usage = herdr.ClaudeUsage
	case "codex":
		a.Usage = herdr.CodexUsage
	case "opencode":
		a.Usage = herdr.OpenCodeUsage
	}
	return a
}

// rotationTick is the checkout-owner state machine. Occupancy, tool activity,
// and pane status are all read from the persisted harness session identity;
// any unknown source is recorded and never treated as zero usage.
func (w *worker) rotationTick(ctx context.Context, id string, s herdr.Session) {
	// Claude Code owns its context threshold through the installed
	// context-handoff hook. A changed HANDOFF.md means that hook has landed a
	// durable local continuation. Resume in the same process with Claude's
	// native context reset instead of manufacturing Orchestra's cross-worker
	// release artifact. Codex and OpenCode continue through the existing
	// occupancy/release state machine below.
	if w.harness == "claude" {
		if err := w.advanceClaudeContextReset(ctx, id, s); err != nil {
			w.recordError(fmt.Errorf("Claude context reset %s: %w", id, err))
		}
		// A turn boundary is not a rotation. Claude owns its context rollover
		// through the installed hook, which is why the occupancy state machine
		// below is skipped, but phase requests and human decisions are carried
		// at the boundary and returning here left both unreachable on this
		// harness. Every decision recorded against a live Claude session went
		// undelivered, and no phase request could ever be read.
		t, ok := w.tasks[id]
		if !ok {
			w.recordError(fmt.Errorf("turn boundary %s: task cache missing", id))
			return
		}
		p, err := w.project(t)
		if err != nil {
			w.recordError(err)
			return
		}
		w.federatedTurn(ctx, id, w.adapter(s, p.Remote), orchestrator.TurnContinue)
		return
	}
	t, ok := w.tasks[id]
	if !ok {
		w.recordError(fmt.Errorf("rotation %s: task cache missing", id))
		return
	}
	p, err := w.project(t)
	if err != nil {
		w.recordError(err)
		return
	}
	a := w.adapter(s, p.Remote)
	resolved, err := a.ResolveSessionIdentity(s)
	if err != nil {
		w.recordError(fmt.Errorf("rotation %s occupancy degraded: %w", id, err))
		return
	}
	// DeepEqual, not !=: Session carries a slice since decisions are tracked
	// per session, so it is no longer comparable with ==.
	if !reflect.DeepEqual(resolved, s) {
		w.sessions[id] = resolved
		s = resolved
		_ = w.save()
	}
	d := (orchestrator.RotationStateMachine{Soft: w.soft, Hard: w.hard}).Evaluate(ctx, a, s)
	if d.ActivityDegraded != nil {
		w.recordError(fmt.Errorf("rotation %s activity degraded: %w", id, d.ActivityDegraded))
	}
	if d.Degraded != nil {
		w.recordError(fmt.Errorf("rotation %s degraded: %w", id, d.Degraded))
		if d.Action == orchestrator.TurnContinue || d.Action == "" {
			return
		}
	}
	if d.Action == orchestrator.TurnContinue || d.Action == "" {
		w.federatedTurn(ctx, id, a, orchestrator.TurnContinue)
		return
	}
	if d.Action == orchestrator.TurnRefuse || s.HandoffRequested {
		return
	}
	if d.Reason == "milestone" || d.Reason == "thrash" {
		if err := a.RequestHandoffReason(ctx, s, d.Reason, d.DeadEnds); err != nil {
			w.recordError(fmt.Errorf("rotation %s %s prompt: %w", id, d.Reason, err))
			return
		}
	} else if err := a.RequestHandoff(ctx, s); err != nil {
		w.recordError(fmt.Errorf("rotation %s threshold prompt: %w", id, err))
		return
	}
	s.HandoffRequested, s.HandoffReason = true, d.Reason
	w.sessions[id] = s
	_ = w.save()
}

func (w *worker) sendLine(ctx context.Context, s herdr.Session, line string) error {
	backend := w.executionBackend()
	if backend == nil {
		return fmt.Errorf("execution backend is not configured")
	}
	if err := backend.SendText(ctx, s, line); err != nil {
		return fmt.Errorf("send %q: %w", line, err)
	}
	if err := backend.SendKeys(ctx, s, []string{"ENTER"}); err != nil {
		return fmt.Errorf("submit %q: %w", line, err)
	}
	// A lost Enter here leaves the session mid-rollover with /clear sitting in
	// the editor, which is worse than a lost launch: nothing retries it.
	if err := w.confirmInput(ctx, s, line); err != nil {
		return fmt.Errorf("submit %q: %w", line, err)
	}
	return nil
}

func (w *worker) advanceClaudeContextReset(ctx context.Context, id string, s herdr.Session) error {
	backend := w.executionBackend()
	if backend == nil {
		return fmt.Errorf("execution backend is not configured")
	}
	if s.ContextResetSHA == "" {
		sha, err := fileSHA256(filepath.Join(s.Worktree, "HANDOFF.md"))
		if os.IsNotExist(err) {
			return nil
		}
		if err != nil {
			return fmt.Errorf("read HANDOFF.md: %w", err)
		}
		if sha == s.ContextHandoffSHA {
			return nil
		}
		status, err := backend.AgentStatus(ctx, s)
		if err != nil {
			return fmt.Errorf("confirm Claude stopped after handoff: %w", err)
		}
		if status != "idle" {
			return nil
		}
		s.ContextResetSHA = sha
		s.ContextResetPhase = "clear"
		w.sessions[id] = s
		if err := w.save(); err != nil {
			return err
		}
	}

	switch s.ContextResetPhase {
	case "clear":
		if err := w.sendLine(ctx, s, "/clear"); err != nil {
			return err
		}
		s.ContextResetPhase = "handoff"
		w.sessions[id] = s
		if err := w.save(); err != nil {
			return err
		}
		// /clear redraws Claude's input UI asynchronously. Give it a small,
		// bounded interval before submitting the new-session file mention.
		select {
		case <-ctx.Done():
			return ctx.Err()
		case <-time.After(500 * time.Millisecond):
		}
		fallthrough
	case "handoff":
		if err := w.sendLine(ctx, s, "@HANDOFF.md"); err != nil {
			return err
		}
		s.ContextHandoffSHA = s.ContextResetSHA
		s.ContextResetSHA = ""
		s.ContextResetPhase = ""
		// Claude normally opens a fresh transcript for /clear. Force the next
		// observation to discover it instead of retaining the exhausted path.
		s.SessionFile = ""
		w.sessions[id] = s
		return w.save()
	default:
		return fmt.Errorf("unknown persisted context-reset phase %q", s.ContextResetPhase)
	}
}

func (w *worker) advanceRelease(ctx context.Context, id string, s herdr.Session) {
	t, ok := w.tasks[id]
	if !ok {
		w.recordError(fmt.Errorf("release %s: task cache missing", id))
		return
	}
	p, err := w.project(t)
	if err != nil {
		w.recordError(fmt.Errorf("release %s: %w", id, err))
		return
	}
	if w.releases == nil {
		w.releases = map[string]releaseTransaction{}
	}
	tx := w.releases[id]
	if tx.ID == "" {
		l, ok := w.leases[id]
		if !ok {
			w.recordError(fmt.Errorf("release %s: lease missing", id))
			return
		}
		tx = releaseTransaction{ID: domain.NewID(), LeaseVersion: l.Version, Phase: "prepared", UpdatedAt: time.Now().UTC()}
		w.releases[id] = tx
		_ = w.save()
	}
	a := w.adapter(s, p.Remote)
	if tx.Phase == "prepared" {
		prepared, err := a.PrepareRelease(ctx, s)
		if err != nil {
			tx.LastError, tx.UpdatedAt = err.Error(), time.Now().UTC()
			w.releases[id] = tx
			_ = w.save()
			w.recordError(fmt.Errorf("release %s prepare: %w", id, err))
			return
		}
		tx.Ref, tx.AnchorSHA, tx.Phase, tx.LastError, tx.UpdatedAt = prepared.Ref, prepared.AnchorSHA, "anchor_pushed", "", time.Now().UTC()
		w.releases[id] = tx
		_ = w.save()
	}
	if tx.Phase == "anchor_pushed" {
		l := w.leases[id]
		if err := w.api.Release(ctx, id, tx.Ref, tx.AnchorSHA, tx.ID, l.Epoch, tx.LeaseVersion, w.sessionEvidence(ctx, id, s)); err != nil {
			tx.LastError, tx.UpdatedAt = err.Error(), time.Now().UTC()
			w.releases[id] = tx
			_ = w.save()
			w.recordError(fmt.Errorf("release %s commit: %w", id, err))
			return
		}
		tx.Phase, tx.LastError, tx.UpdatedAt = "event_committed", "", time.Now().UTC()
		w.releases[id] = tx
		_ = w.save()
	}
	if tx.Phase == "event_committed" && !tx.AgentReleased {
		if err := a.ReleaseAgent(ctx, s); err != nil {
			tx.LastError, tx.UpdatedAt = err.Error(), time.Now().UTC()
			w.releases[id] = tx
			_ = w.save()
			w.recordError(fmt.Errorf("release %s release agent: %w", id, err))
			return
		}
		tx.AgentReleased, tx.LastError, tx.UpdatedAt = true, "", time.Now().UTC()
		w.releases[id] = tx
		_ = w.save()
	}
	if tx.Phase == "pickup_validated" {
		if err := a.Kill(ctx, s); err != nil {
			tx.LastError, tx.UpdatedAt = err.Error(), time.Now().UTC()
			w.releases[id] = tx
			_ = w.save()
			w.recordError(fmt.Errorf("release %s retire predecessor: %w", id, err))
			return
		}
		_ = os.Remove(filepath.Join(s.Worktree, herdr.HandoffReportFile))
		tx.Phase, tx.UpdatedAt = "predecessor_retired", time.Now().UTC()
		w.releases[id] = tx
		_ = w.save()
		delete(w.sessions, id)
		delete(w.releases, id)
		_ = w.save()
	}
}

// ackPickup retries the successor acknowledgement from persisted lease state.
// It is safe after a lost response: the coordinator recognizes the exact
// transaction/lease epoch as an idempotent pickup.
func (w *worker) ackPickup(ctx context.Context, id string, s herdr.Session) error {
	l, ok := w.leases[id]
	if !ok || l.HandoffRef == "" || l.TransactionID == "" || l.AnchorSHA == "" {
		return fmt.Errorf("pickup %s: lease is missing its release transaction", id)
	}
	if l.PickupAcknowledged {
		return nil
	}
	if err := w.api.Pickup(ctx, id, l.HandoffRef, l.AnchorSHA, l.TransactionID, l.Epoch, l.Version, w.sessionEvidence(ctx, id, s)); err != nil {
		return fmt.Errorf("pickup %s acknowledgement: %w", id, err)
	}
	l.PickupAcknowledged = true
	l.Version++ // TaskPickupValidated increments the task version.
	w.leases[id] = l
	return w.save()
}

func (w *worker) sessionEvidence(ctx context.Context, taskID string, s herdr.Session) domain.SessionEvidence {
	e := domain.SessionEvidence{PaneID: s.PaneID, HarnessID: w.harnessID, PaneState: "open", Source: "worker", CheckedAt: time.Now().UTC()}
	text, err := (herdr.CLIAdapter{Backend: w.executionBackend(), Harness: w.harness}).PaneCapture(ctx, s, "recent")
	if err != nil {
		e.PaneState = "unreachable"
		return e
	}
	if capture, err := w.api.PublishCapture(ctx, federation.Capture{TaskID: taskID, PaneID: s.PaneID, Text: text}); err == nil {
		e.CapturedAt = capture.At
	}
	return e
}

func (w *worker) usageReceipt(s herdr.Session, l lease) map[string]any {
	if s.SessionFile == "" && !(w.harness == "opencode" && s.SessionID != "") {
		return map[string]any{"harness_id": w.harnessID, "consumed": 0, "known": false, "error": "native usage identity missing"}
	}
	var usage herdr.Usage
	var err error
	switch w.harness {
	case "claude":
		usage, err = herdr.ClaudeUsage(s.SessionFile)
	case "codex":
		usage, err = herdr.CodexUsage(s.SessionFile)
	case "opencode":
		usage, err = herdr.OpenCodeSessionUsage(s.SessionID)
	}
	if err != nil {
		return map[string]any{"harness_id": w.harnessID, "consumed": 0, "known": false, "error": err.Error()}
	}
	delta := float64(usage.Numerator()) - l.UsageBaseline
	if delta < 0 {
		delta = 0
	}
	return map[string]any{"harness_id": w.harnessID, "input_tokens": usage.Input, "cache_read_tokens": usage.CacheRead, "cache_write_tokens": usage.CacheWrite, "consumed": delta, "lease_usage_delta": delta, "known": true}
}

func git(ctx context.Context, dir string, args ...string) ([]byte, error) {
	return exec.CommandContext(ctx, "git", append([]string{"-C", dir}, args...)...).CombinedOutput()
}

// finalize performs only mechanical delivery work. It never asks the harness
// to narrate Git state, gates, or a report; those are generated from the
// worker-owned checkout and then verified against the configured remote.
func (w *worker) finalize(ctx context.Context, id string, s herdr.Session) (completionEvidence, error) {
	t, ok := w.tasks[id]
	if !ok {
		return completionEvidence{}, fmt.Errorf("task cache missing")
	}
	p, err := w.project(t)
	if err != nil {
		return completionEvidence{}, err
	}
	if s.TaskFileSHA != "" {
		if err := continuity.VerifyTaskFile(s.Worktree, s.TaskFileSHA); err != nil {
			return completionEvidence{}, fmt.Errorf("verify immutable TASK.md: %w", err)
		}
	}
	base, err := git(ctx, s.Worktree, "rev-parse", "HEAD")
	if err != nil {
		return completionEvidence{}, fmt.Errorf("base sha: %s: %w", base, err)
	}
	e := completionEvidence{TaskID: id, Project: t.Project, Worker: w.harnessID, Harness: w.harness, PaneID: s.PaneID, BaseSHA: strings.TrimSpace(string(base)), Remote: p.Remote, QualityGate: t.QualityGate, CompletedAt: time.Now().UTC()}
	if _, err := git(ctx, s.Worktree, "diff", "--quiet", "--", "TASK.md"); err != nil {
		return completionEvidence{}, errors.New("TASK.md was modified")
	}
	if out, err := git(ctx, s.Worktree, "add", "-A", "--", ".", stageExclude); err != nil {
		return completionEvidence{}, fmt.Errorf("stage result: %s: %w", out, err)
	}
	if _, err := git(ctx, s.Worktree, "diff", "--cached", "--quiet"); err != nil {
		if out, err := git(ctx, s.Worktree, "commit", "-m", "orchestra: complete "+id); err != nil {
			return completionEvidence{}, fmt.Errorf("commit result: %s: %w", out, err)
		}
	}
	sha, err := git(ctx, s.Worktree, "rev-parse", "HEAD")
	if err != nil {
		return completionEvidence{}, fmt.Errorf("result sha: %s: %w", sha, err)
	}
	e.ResultSHA = strings.TrimSpace(string(sha))
	// The gate runs after the result commit, against a clean tree that is
	// byte-for-byte the commit being submitted. Running it first bound the
	// evidence to the pre-commit HEAD, which CheckSubmission rejects because
	// gate sha, review sha and head sha must be one commit.
	gateCommand := t.QualityGate
	if gateCommand == "" {
		gateCommand = p.QualityGate
	}
	e.QualityGate = gateCommand
	if gateCommand != "" {
		gate := exec.CommandContext(ctx, "sh", "-c", gateCommand)
		gate.Dir = s.Worktree
		out, gateErr := gate.CombinedOutput()
		e.GateOutput = tail(string(out), review.MaxGateOutputBytes)
		if gateErr != nil {
			e.GateExit = 1
			return completionEvidence{}, fmt.Errorf("quality gate %q: %s: %w", gateCommand, out, gateErr)
		}
	}
	// The submission branch is derived, not the worktree's local name: the
	// coordinator computes "orchestra/<task>" independently, and a pull
	// request can only be opened for a branch both halves name the same way.
	e.Branch = "orchestra/" + id
	if out, err := git(ctx, s.Worktree, "push", p.Remote, "HEAD:refs/heads/"+e.Branch); err != nil {
		return completionEvidence{}, fmt.Errorf("push result: %s: %w", out, err)
	}
	remote, err := git(ctx, s.Worktree, "ls-remote", p.Remote, "refs/heads/"+e.Branch)
	if err != nil || !strings.HasPrefix(string(remote), e.ResultSHA+"\t") {
		return completionEvidence{}, fmt.Errorf("verify pushed sha: got %q: %w", strings.TrimSpace(string(remote)), err)
	}
	return e, nil
}

// reviewFile is where the reviewing session leaves its findings. The reviewer
// supplies findings and nothing else: the commit they are bound to is the
// result commit the worker just made, which the agent cannot know and must not
// assert.
const reviewFile = "review.json"

// errReviewArtifact is a refusal only the reviewing agent can fix. It is
// separated from every other submission failure because recording it in worker
// health alone would leave a live session being retried every five seconds
// with nothing telling it what is wrong — the silent-loop shape this codebase
// keeps producing (F39, F42).
var errReviewArtifact = errors.New("review artifact")

// answerRefusedReview tells the reviewing session why its finish was refused
// and clears the done marker so a corrected artifact is what finishes the
// phase. The refusal survives a failed send: the marker is dropped either way,
// and the agent writes it again when it has written the file.
func (w *worker) answerRefusedReview(ctx context.Context, id string, s herdr.Session, cause error) {
	text := "Orchestra refused your completion: " + cause.Error() +
		"\n\nWrite .orchestra/" + reviewFile + " as {\"findings\": [...]}, an empty list if you found nothing, then write .orchestra/done again. Do not set a commit sha."
	if err := w.sendPrompt(ctx, s, text); err != nil {
		w.recordError(fmt.Errorf("deliver review refusal %s: %w", id, err))
	}
	if err := os.Remove(filepath.Join(s.Worktree, ".orchestra", "done")); err != nil {
		w.recordError(fmt.Errorf("clear done marker %s: %w", id, err))
	}
	log.Printf("completion %s refused: %v", id, cause)
}

// submit seals the review and hands the result to the human through a pull
// request. It is the only path from a reviewed change to TaskSubmitted; the
// direct completion call remains for a project with no forge configured.
func (w *worker) submit(ctx context.Context, id string, s herdr.Session, e completionEvidence) (string, error) {
	var result review.Result
	b, err := os.ReadFile(filepath.Join(s.Worktree, ".orchestra", reviewFile))
	if err != nil {
		// An absent review file is not a pass. Submission needs a sealed
		// review, and inventing an empty one would launder "the reviewer wrote
		// nothing" into "the reviewer found nothing".
		return "", fmt.Errorf("%w: the review phase sealed no .orchestra/%s: %v", errReviewArtifact, reviewFile, err)
	}
	if err := json.Unmarshal(b, &result); err != nil {
		return "", fmt.Errorf("%w: .orchestra/%s is not valid JSON: %v", errReviewArtifact, reviewFile, err)
	}
	result.ResultSHA = e.ResultSHA
	if err := result.Validate(); err != nil {
		return "", fmt.Errorf("%w: .orchestra/%s: %v", errReviewArtifact, reviewFile, err)
	}
	l := w.leases[id]
	// The gate result is bound to the commit the gate ran against, which
	// finalize guarantees is the commit being submitted. A project with no
	// quality gate still produces a bound result: Passed() needs the sha.
	gate := domain.GateResult{Command: e.QualityGate, ExitCode: e.GateExit, SHA: e.ResultSHA, Output: e.GateOutput}
	return w.api.Submit(ctx, id, l.Epoch, l.Version, e.ResultSHA, e.Remote, result, gate)
}

// stageExclude keeps Orchestra's own control files out of the result commit.
// It names the directory, not the marker inside it: .orchestra carries a
// .gitignore of "*" (herdr/adapter.go), and naming an ignored file in a
// pathspec makes git refuse the whole add with "The following paths are
// ignored by one of your .gitignore files". F42, live on run 5: the review
// agent wrote .orchestra/done, and every completion attempt failed on that
// refusal, once every five seconds, with the task stuck in review. Excluding
// the directory also holds for a worktree that has no inner .gitignore.
const stageExclude = ":!.orchestra"

func (w *worker) renewLeases(ctx context.Context) {
	if w.executionBackend() == nil {
		return
	}
	now := time.Now()
	for taskID, l := range w.leases {
		s, ok := w.sessions[taskID]
		if !ok || l.Version == 0 || l.Until.After(now.Add(domain.LeaseRenewAt)) {
			continue
		}
		adapter := herdr.CLIAdapter{Backend: w.executionBackend(), Harness: w.harness}
		// Input lines are excluded: keystrokes arriving at a pane, from
		// Orchestra or from anyone else, are not the agent doing work.
		text, err := w.paneProgress(ctx, adapter, s)
		if err != nil {
			w.recordError(fmt.Errorf("validate lease %s: %w", taskID, err))
			continue
		}
		// A live pane is not progress. Renewing on pane existence alone let a
		// pane that opened and never started hold its lease forever, which is
		// what orphaned the July task once the launch itself had failed.
		status, err := adapter.AgentStatus(ctx, s)
		if err != nil {
			w.recordError(fmt.Errorf("validate lease %s: %w", taskID, err))
			continue
		}
		progress := domain.Hash([]byte(text))
		switch {
		case herdr.IsBusy(status):
		case progress != l.ProgressSHA && l.ProgressSHA != "":
		case l.ProgressSHA == "":
			// First renewal has no baseline to compare against. Record one and
			// allow this renewal; the next one must show real movement.
		default:
			w.recordError(fmt.Errorf("lease %s not renewed: agent status %s and pane unchanged since the last renewal", taskID, status))
			continue
		}
		if err := w.api.Renew(ctx, taskID, l.Epoch, l.Version, int(domain.LeaseTTL.Seconds())); err != nil {
			w.recordError(fmt.Errorf("renew lease %s: %w", taskID, err))
			log.Printf("renew lease %s: %v", taskID, err)
		} else {
			// RenewLease appends one event. Retain that epoch locally until its
			// replay arrives so a release transaction uses the same version.
			l.Version++
			l.Until = now.Add(domain.LeaseTTL)
			l.ProgressSHA = progress
			w.leases[taskID] = l
			_ = w.save()
		}
	}
}

// publishCaptures makes remote panes observable without allowing the
// coordinator to touch their unix herdr socket.
func (w *worker) publishCaptures(ctx context.Context) {
	for taskID, session := range w.sessions {
		text, err := (herdr.CLIAdapter{Backend: w.executionBackend(), Harness: w.harness}).PaneCapture(ctx, session, "recent")
		if err != nil {
			continue
		}
		if _, err := w.api.PublishCapture(ctx, federation.Capture{TaskID: taskID, PaneID: session.PaneID, Text: text}); err != nil {
			log.Printf("publish capture %s: %v", taskID, err)
		}
	}
}

type approvalInput struct {
	Text string
	Keys []string
}

func approvalResponse(text, kind string) (approvalInput, bool) {
	low := strings.ToLower(text)
	// Never invent a keystroke. y/n prompts label both decisions directly.
	if strings.Contains(low, "[y/n]") || strings.Contains(low, "(y/n)") {
		if kind == "grant_approval" {
			return approvalInput{Text: "y\n"}, true
		}
		return approvalInput{Text: "n\n"}, true
	}
	// OpenCode's explicit selector states "Allow once  Allow always  Reject"
	// and "enter confirm". Send a real ENTER key, not a newline through
	// pane.send_text: OpenCode's selector does not treat the latter as input.
	// Enter is consequently a bounded one-time grant;
	// rejection would require unobservable selector navigation, so refuse it.
	if kind == "grant_approval" && strings.Contains(low, "allow once") && strings.Contains(low, "allow always") && strings.Contains(low, "reject") && strings.Contains(low, "enter confirm") {
		return approvalInput{Keys: []string{"ENTER"}}, true
	}
	return approvalInput{}, false
}
func (w *worker) runCommands(ctx context.Context) {
	commands, err := w.api.Commands(ctx)
	if err != nil {
		log.Printf("poll controls: %v", err)
		return
	}
	for _, command := range commands {
		session, ok := w.sessions[command.TaskID]
		if !ok || session.PaneID != command.PaneID {
			_ = w.api.ResolveCommand(ctx, command.ID, "stale", "session or pane changed")
			continue
		}
		text, err := (herdr.CLIAdapter{Backend: w.executionBackend(), Harness: w.harness}).PaneCapture(ctx, session, "recent")
		if err != nil {
			_ = w.api.ResolveCommand(ctx, command.ID, "rejected", "capture unavailable: "+err.Error())
			continue
		}
		capture, err := w.api.PublishCapture(ctx, federation.Capture{TaskID: command.TaskID, PaneID: session.PaneID, Text: text})
		if err != nil {
			_ = w.api.ResolveCommand(ctx, command.ID, "rejected", "cannot publish capture: "+err.Error())
			continue
		}
		if capture.Revision != command.CaptureRevision {
			_ = w.api.ResolveCommand(ctx, command.ID, "stale", "capture revision changed")
			continue
		}
		if command.Kind == "resubmit" {
			// Not an approval: the pane is holding input Orchestra already
			// submitted and believes it delivered. Press Enter and say so.
			if err := w.executionBackend().SendKeys(ctx, session, []string{"Enter"}); err != nil {
				_ = w.api.ResolveCommand(ctx, command.ID, "rejected", "resubmit not delivered: "+err.Error())
				continue
			}
			log.Printf("resubmit %s: Enter resent to %s at capture revision %d", command.TaskID, session.PaneID, command.CaptureRevision)
			if err := w.api.ResolveCommand(ctx, command.ID, "acknowledged", ""); err != nil {
				log.Printf("ack command %s: %v", command.ID, err)
			}
			continue
		}
		input, ok := approvalResponse(text, command.Kind)
		if !ok {
			_ = w.api.ResolveCommand(ctx, command.ID, "rejected", "prompt does not expose an executable approval control")
			continue
		}
		backend := w.executionBackend()
		var inputErr error
		if len(input.Keys) > 0 {
			inputErr = backend.SendKeys(ctx, session, input.Keys)
		} else {
			inputErr = backend.SendText(ctx, session, input.Text)
		}
		if inputErr != nil {
			_ = w.api.ResolveCommand(ctx, command.ID, "rejected", backend.Kind()+" backend did not acknowledge input: "+inputErr.Error())
			continue
		}
		if err := w.api.ResolveCommand(ctx, command.ID, "acknowledged", ""); err != nil {
			log.Printf("ack command %s: %v", command.ID, err)
		}
	}
}

func (w *worker) once(ctx context.Context) error {
	es, _, err := w.api.Events(ctx, w.cursor)
	if err != nil {
		return err
	}
	for _, e := range es {
		if t, ok := created(e); ok {
			w.tasks[t.ID] = t
		}
		if e.Type == "TaskLeased" {
			var p struct {
				HarnessID     string `json:"harness_id"`
				Epoch         string `json:"lease_epoch"`
				HandoffRef    string `json:"handoff_ref"`
				TransactionID string `json:"transaction_id"`
				AnchorSHA     string `json:"anchor_sha"`
			}
			if json.Unmarshal(e.Payload, &p) == nil && p.HarnessID == w.harnessID {
				var until struct {
					UntilNS int64 `json:"until_ns"`
				}
				_ = json.Unmarshal(e.Payload, &until)
				w.leases[e.TaskID] = lease{Epoch: p.Epoch, HandoffRef: p.HandoffRef, TransactionID: p.TransactionID, AnchorSHA: p.AnchorSHA, Version: e.Version, Until: time.Unix(0, until.UntilNS)}
			}
		}
		if e.Type == "TaskLeaseRenewed" {
			var p struct {
				HarnessID string `json:"harness_id"`
				Epoch     string `json:"lease_epoch"`
				UntilNS   int64  `json:"until_ns"`
			}
			if json.Unmarshal(e.Payload, &p) == nil && p.HarnessID == w.harnessID {
				l := w.leases[e.TaskID]
				l.Version, l.Epoch, l.Until = e.Version, p.Epoch, time.Unix(0, p.UntilNS)
				w.leases[e.TaskID] = l
			}
		}
		if e.Type == "TaskLaunchAcknowledged" {
			if l, ok := w.leases[e.TaskID]; ok {
				l.Version = e.Version
				w.leases[e.TaskID] = l
			}
		}
		if e.Type == "TaskNeedsAttention" {
			// The diagnostic event increments the aggregate version but leaves
			// ownership intact. Keep our locally persisted expected version in
			// sync so a late, otherwise valid completion is not self-staled.
			if l, ok := w.leases[e.TaskID]; ok {
				l.Version = e.Version
				w.leases[e.TaskID] = l
			}
		}
		if e.Type == "TaskCompleted" {
			delete(w.leases, e.TaskID)
			if session, active := w.sessions[e.TaskID]; active {
				if w.executionBackend() == nil {
					delete(w.sessions, e.TaskID)
				} else if err := (herdr.CLIAdapter{Backend: w.executionBackend(), Harness: w.harness}).Kill(ctx, session); err != nil {
					w.quarantined[e.TaskID] = true
					w.recordError(fmt.Errorf("close completed pane %s: %w", e.TaskID, err))
					continue
				} else {
					_ = os.Remove(filepath.Join(session.Worktree, ".orchestra", "done"))
					_ = os.Remove(filepath.Join(session.Worktree, ".orchestra"))
					delete(w.sessions, e.TaskID)
				}
			}
		}
		if e.Type == "TaskPickupValidated" {
			var p struct {
				TransactionID string `json:"transaction_id"`
			}
			if json.Unmarshal(e.Payload, &p) == nil {
				if tx := w.releases[e.TaskID]; tx.ID != "" && tx.ID == p.TransactionID {
					tx.Phase, tx.UpdatedAt = "pickup_validated", time.Now().UTC()
					w.releases[e.TaskID] = tx
				}
			}
			if l, ok := w.leases[e.TaskID]; ok {
				l.Version = e.Version
				w.leases[e.TaskID] = l
			}
		}
		if e.Type == "TaskReleased" || e.Type == "TaskFailed" || e.Type == "TaskBlocked" {
			if e.Type == "TaskReleased" {
				var p struct {
					TransactionID string `json:"transaction_id"`
				}
				if json.Unmarshal(e.Payload, &p) == nil {
					if tx := w.releases[e.TaskID]; tx.ID != "" && tx.ID == p.TransactionID && tx.Phase == "anchor_pushed" {
						tx.Phase, tx.LastError, tx.UpdatedAt = "event_committed", "", time.Now().UTC()
						w.releases[e.TaskID] = tx
					}
				}
			}
			delete(w.leases, e.TaskID)
			// A releasing predecessor remains intentionally recoverable until
			// TaskPickupValidated for its transaction. Do not erase its pane
			// mapping merely because our own release event was replayed.
			//
			// Recoverable means an anchor was actually pushed. Before that
			// tx.Ref is empty and no successor can pick anything up, so the
			// mapping protects nothing. F30: a transaction stuck at "prepared"
			// held the session forever once its pane was gone, health() kept
			// reporting ActiveTask, and the harness never leased again.
			tx, releasing := w.releases[e.TaskID]
			if !releasing || tx.Ref == "" {
				if releasing {
					delete(w.releases, e.TaskID)
				}
				if session, active := w.sessions[e.TaskID]; active {
					w.quarantine(ctx, e.TaskID, session)
				}
			}
		}
		if e.Seq > w.cursor {
			w.cursor = e.Seq
		}
	}
	// A coordinator restart can restore its task snapshot without retaining
	// the in-memory event tail. In that state a worker with a persisted cursor
	// receives an empty page even though a lease is currently assigned to it.
	// Reconcile the authoritative projection before treating an empty page as
	// "nothing to do"; otherwise the lease remains invisible until expiry.
	if len(es) == 0 {
		if err := w.reconcileLeases(ctx); err != nil {
			return err
		}
	}
	// State is only a cache. If a lease survived but its TaskCreated event is
	// older than the worker's cursor (or the event has been compacted), hydrate
	// the authoritative task projection before deciding whether to start.
	for taskID := range w.leases {
		if _, ok := w.tasks[taskID]; !ok {
			tasks, err := w.api.Tasks(ctx)
			if err != nil {
				return fmt.Errorf("hydrate leased task %s: %w", taskID, err)
			}
			for _, task := range tasks {
				w.tasks[task.ID] = task
			}
			break
		}
	}
	// Project the whole batch before launching. This prevents a new worker
	// from resurrecting every historical lease during its initial replay.
	for taskID, l := range w.leases {
		if _, started := w.sessions[taskID]; started {
			continue
		}
		if t, ok := w.tasks[taskID]; ok {
			if err := w.start(ctx, t, l.HandoffRef); err != nil {
				log.Printf("lease %s: %v", t.ID, err)
				_, started := w.sessions[taskID]
				class := classifyLaunchError(err, started)
				var evidence domain.SessionEvidence
				if session, ok := w.sessions[taskID]; ok {
					evidence = w.sessionEvidence(ctx, taskID, session)
				}
				if nackErr := w.api.NackStart(ctx, taskID, l.Epoch, l.Version, class, err.Error(), evidence); nackErr != nil {
					w.recordError(fmt.Errorf("nack launch %s: %w", taskID, nackErr))
					continue
				}
				if class != "launch_uncertain" {
					delete(w.leases, taskID)
				}
			}
		}
	}
	// Unit/replay-only workers intentionally have no execution backend. A
	// production worker always does, and only then participates in the live
	// capture/control protocol.
	if w.executionBackend() != nil {
		w.publishCaptures(ctx)
		w.runCommands(ctx)
		w.renewLeases(ctx)
	}
	w.retryQuarantines(ctx)
	w.releaseReady(ctx)
	if err := w.save(); err != nil {
		return err
	}
	return w.api.Ack(ctx, w.cursor)
}

func (w *worker) reconcileLeases(ctx context.Context) error {
	tasks, err := w.api.Tasks(ctx)
	if err != nil {
		return fmt.Errorf("reconcile leased tasks: %w", err)
	}
	active := make(map[string]lease)
	for _, task := range tasks {
		w.tasks[task.ID] = task
		if (task.State == domain.StateLeased || task.State == domain.StateNeedsAttention) && task.Lease != nil && task.Lease.HarnessID == w.harnessID {
			active[task.ID] = lease{Epoch: task.Lease.Epoch, HandoffRef: task.HandoffRef, TransactionID: task.ReleaseTransaction, AnchorSHA: task.ReleaseAnchor, Version: task.Version, Until: task.Lease.Until}
		}
	}
	for taskID := range w.leases {
		if _, ok := active[taskID]; !ok {
			delete(w.leases, taskID)
		}
	}
	for taskID, l := range active {
		// The coordinator is authoritative for the lease, not for what this
		// worker has observed under it. Rebuilding the struct wholesale wiped
		// every worker-local field each tick, which silently disabled the
		// renewal progress check and reset the usage baseline. Carry them
		// across, but only while the epoch is the same lease.
		if prev, ok := w.leases[taskID]; ok && prev.Epoch == l.Epoch {
			l.ProgressSHA = prev.ProgressSHA
			l.UsageBaseline = prev.UsageBaseline
			l.PickupAcknowledged = prev.PickupAcknowledged
		}
		w.leases[taskID] = l
	}
	return nil
}

// reRegisterAfterCoordinatorRestart restores the coordinator's in-memory
// worker registry. A worker must survive a server restart without operator
// intervention; its persisted cursor and sessions remain valid.
func (w *worker) reRegisterAfterCoordinatorRestart(ctx context.Context, cause error) bool {
	if cause == nil || !strings.Contains(cause.Error(), "401 Unauthorized: unknown worker") {
		return false
	}
	if err := w.api.Register(ctx, w.registration); err != nil {
		log.Printf("re-register: %v", err)
		return false
	}
	log.Printf("re-registered after coordinator restart")
	return true
}
func required(k string) string {
	v := os.Getenv(k)
	if v == "" {
		log.Fatalf("%s required", k)
	}
	return v
}

// harnessSpec is one harness identity this process serves. Each spec becomes a
// separate federation identity because the coordinator authorizes lease calls by
// comparing the URL's worker id against the lease's harness id
// (cmd/orchestra/main.go). One process may therefore hold several identities,
// but it may never present one identity for several harnesses.
type harnessSpec struct {
	ID      string `json:"id"`
	Harness string `json:"harness"`
	Token   string `json:"token,omitempty"`
	Backend string `json:"backend,omitempty"`
	// Herdr is the JSON-RPC address for Backend "herdr".
	Herdr string `json:"herdr,omitempty"`
	// TmuxSocket and Command configure Backend "tmux".
	TmuxSocket string `json:"tmux_socket,omitempty"`
	Command    string `json:"command,omitempty"`
	State      string `json:"state,omitempty"`
	Address    string `json:"address,omitempty"`
}

// tokenEnvKey maps a harness id onto a per-identity token variable, so a
// multi-harness deployment keeps its tokens in the protected environment file
// rather than in the harness config file.
func tokenEnvKey(id string) string {
	var b strings.Builder
	b.WriteString("ORCHESTRA_WORKER_TOKEN_")
	for _, r := range strings.ToUpper(id) {
		if (r >= 'A' && r <= 'Z') || (r >= '0' && r <= '9') {
			b.WriteRune(r)
			continue
		}
		b.WriteRune('_')
	}
	return b.String()
}

// harnessSpecs reads the multi-harness declaration, falling back to the legacy
// single-harness environment so an existing deployment upgrades unchanged.
func harnessSpecs() []harnessSpec {
	path := os.Getenv("ORCHESTRA_WORKER_HARNESS_CONFIG_FILE")
	if path == "" {
		return []harnessSpec{{
			ID:         required("ORCHESTRA_WORKER_HERDR_ID"),
			Harness:    required("ORCHESTRA_WORKER_HARNESS"),
			Token:      required("ORCHESTRA_WORKER_TOKEN"),
			Backend:    os.Getenv("ORCHESTRA_WORKER_BACKEND"),
			Herdr:      os.Getenv("ORCHESTRA_WORKER_HERDR"),
			TmuxSocket: os.Getenv("ORCHESTRA_WORKER_TMUX_SOCKET"),
			Command:    os.Getenv("ORCHESTRA_WORKER_HARNESS_COMMAND"),
			State:      os.Getenv("ORCHESTRA_WORKER_STATE"),
			Address:    os.Getenv("ORCHESTRA_WORKER_ADDRESS"),
		}}
	}
	b, err := os.ReadFile(path)
	if err != nil {
		log.Fatalf("read ORCHESTRA_WORKER_HARNESS_CONFIG_FILE: %v", err)
	}
	var specs []harnessSpec
	if err := json.Unmarshal(b, &specs); err != nil {
		log.Fatalf("parse ORCHESTRA_WORKER_HARNESS_CONFIG_FILE: %v", err)
	}
	if len(specs) == 0 {
		log.Fatal("ORCHESTRA_WORKER_HARNESS_CONFIG_FILE declares no harnesses")
	}
	seen := map[string]bool{}
	for i, spec := range specs {
		if spec.ID == "" || spec.Harness == "" {
			log.Fatalf("harness %d requires id and harness", i)
		}
		if seen[spec.ID] {
			log.Fatalf("harness id %q is declared twice", spec.ID)
		}
		seen[spec.ID] = true
		if spec.Token == "" {
			key := tokenEnvKey(spec.ID)
			if spec.Token = os.Getenv(key); spec.Token == "" {
				log.Fatalf("harness %s has no token: set %s or its config-file token", spec.ID, key)
			}
			specs[i] = spec
		}
	}
	return specs
}

// statePathFor gives every identity its own state file. Sharing one across
// harnesses would let a persisted session and its lease cross backends, handing
// a tmux backend herdr pane ids it cannot act on. Only the single-harness form
// keeps the historical default path, so an existing deployment recovers its
// sessions after the upgrade instead of orphaning them.
func statePathFor(spec harnessSpec, root, stateDir string, single bool) string {
	switch {
	case spec.State != "":
		return spec.State
	case stateDir != "":
		return filepath.Join(stateDir, "state-"+spec.ID+".json")
	case single:
		return filepath.Join(root, ".orchestra-worker-state.json")
	default:
		return filepath.Join(root, ".orchestra-worker-state-"+spec.ID+".json")
	}
}

// backendFor builds the machine-local execution backend for one harness.
func backendFor(spec harnessSpec) herdr.Backend {
	name := strings.ToLower(strings.TrimSpace(spec.Backend))
	if name == "" {
		name = "herdr"
	}
	switch name {
	case "herdr":
		address := spec.Herdr
		if address == "" {
			log.Fatalf("harness %s: backend herdr requires an address", spec.ID)
		}
		return herdr.New(address)
	case "tmux":
		if spec.Harness != "claude" {
			log.Fatalf("harness %s: backend tmux currently supports only harness claude, got %q", spec.ID, spec.Harness)
		}
		return herdr.NewTmuxBackend(spec.TmuxSocket, spec.Command)
	default:
		log.Fatalf("harness %s: unsupported backend %q (want herdr or tmux)", spec.ID, name)
		return nil
	}
}

func main() {
	workerID := required("ORCHESTRA_WORKER_ID")
	hard := .75
	if v, err := strconv.ParseFloat(os.Getenv("ORCHESTRA_OCCUPANCY_HARD"), 64); err == nil && v > 0 && v < 1 {
		hard = v
	}
	projects := map[string]projectConfig{}
	if path := os.Getenv("ORCHESTRA_WORKER_PROJECT_CONFIG_FILE"); path != "" {
		b, err := os.ReadFile(path)
		if err != nil {
			log.Fatalf("read ORCHESTRA_WORKER_PROJECT_CONFIG_FILE: %v", err)
		}
		if err := json.Unmarshal(b, &projects); err != nil {
			log.Fatalf("parse ORCHESTRA_WORKER_PROJECT_CONFIG_FILE: %v", err)
		}
	} else {
		for _, project := range strings.Split(os.Getenv("ORCHESTRA_WORKER_PROJECTS"), ",") {
			if project = strings.TrimSpace(project); project != "" {
				projects[project] = projectConfig{Repo: required("ORCHESTRA_REPO"), Root: required("ORCHESTRA_WORKTREE_ROOT"), Remote: required("ORCHESTRA_GIT_REMOTE")}
			}
		}
	}
	if len(projects) == 0 {
		// Existing deployments may be upgraded before their protected systemd
		// environment is amended. Stay observable and fail closed in that
		// interval: an empty declaration makes this worker ineligible for all
		// new leases instead of turning a configuration rollout into a crash
		// loop or treating its legacy global checkout as every project.
		log.Printf("no ORCHESTRA_WORKER_PROJECT_CONFIG_FILE/ORCHESTRA_WORKER_PROJECTS; registering with no supported projects")
	}
	for project, config := range projects {
		if config.Repo == "" || config.Root == "" || config.Remote == "" {
			log.Fatalf("project %q requires repo, worktree_root, and remote", project)
		}
	}
	supported := make([]string, 0, len(projects))
	for project := range projects {
		supported = append(supported, project)
	}
	sort.Strings(supported)
	repo, root, remote := required("ORCHESTRA_REPO"), required("ORCHESTRA_WORKTREE_ROOT"), required("ORCHESTRA_GIT_REMOTE")
	if len(supported) > 0 {
		first := projects[supported[0]]
		repo, root, remote = first.Repo, first.Root, first.Remote
	}
	soft, window := .55, int64(200000)
	if v, err := strconv.ParseFloat(os.Getenv("ORCHESTRA_OCCUPANCY_SOFT"), 64); err == nil && v > 0 && v < hard {
		soft = v
	}
	if v, err := strconv.ParseInt(os.Getenv("ORCHESTRA_CONTEXT_WINDOW"), 10, 64); err == nil && v > 0 {
		window = v
	}
	url, admit := required("ORCHESTRA_URL"), os.Getenv("ORCHESTRA_FEDERATION_ADMIT_TOKEN")
	specs := harnessSpecs()
	if len(specs) == 1 && specs[0].ID != workerID {
		// A single-harness deployment keeps the historical invariant: its lease
		// owner and its process identity are the same name.
		log.Fatal("ORCHESTRA_WORKER_ID must equal ORCHESTRA_WORKER_HERDR_ID so leases and offline recovery have one owner")
	}
	stateDir := os.Getenv("ORCHESTRA_WORKER_STATE_DIR")
	workers := make([]*worker, 0, len(specs))
	for _, spec := range specs {
		w := &worker{
			api:         federation.Client{BaseURL: url, WorkerID: spec.ID, Token: spec.Token, AdmitToken: admit},
			harnessID:   spec.ID,
			harness:     spec.Harness,
			repo:        repo,
			root:        root,
			remote:      remote,
			projects:    projects,
			tasks:       map[string]domain.Task{},
			sessions:    map[string]herdr.Session{},
			leases:      map[string]lease{},
			releases:    map[string]releaseTransaction{},
			quarantined: map[string]bool{},
			statePath:   spec.State,
			hard:        hard,
			soft:        soft,
			window:      window,
			// Capacity stays one per identity because a herdr's declared
			// concurrency is one. Serving N harnesses gives the process N slots.
			registration: federation.Worker{ID: spec.ID, Address: spec.Address, Capacity: 1, SupportedProjects: supported, Build: buildinfo.Current()},
		}
		if w.registration.Address == "" {
			w.registration.Address = os.Getenv("ORCHESTRA_WORKER_ADDRESS")
		}
		w.statePath = statePathFor(spec, root, stateDir, len(specs) == 1)
		if err := w.load(); err != nil {
			log.Fatal(err)
		}
		w.backend = backendFor(spec)
		if err := w.api.Register(context.Background(), w.registration); err != nil {
			log.Fatalf("register %s: %v", spec.ID, err)
		}
		// Same reason as the coordinator's: the worker half of the pair must be
		// checkable from journalctl, not only from the coordinator's
		// credentialed worker list.
		b := buildinfo.Current()
		log.Printf("orchestra-worker revision %s built %s dirty %s", b.Revision, b.Time, b.Dirty)
		log.Printf("serving harness %s (%s) on %s backend, state %s", spec.ID, spec.Harness, w.backend.Kind(), w.statePath)
		workers = append(workers, w)
	}
	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
	defer stop()
	ticker := time.NewTicker(5 * time.Second)
	defer ticker.Stop()
	for {
		// Identities are served sequentially. Their checkouts and Git remotes are
		// shared, so concurrent ticks would race two fetch/worktree operations on
		// one repository for no useful latency gain at this fan-out.
		for _, w := range workers {
			if err := w.api.Heartbeat(ctx, w.health(ctx)); err != nil {
				w.recordError(fmt.Errorf("heartbeat: %w", err))
				log.Printf("[%s] heartbeat: %v", w.harnessID, err)
				if w.reRegisterAfterCoordinatorRestart(ctx, err) {
					continue
				}
			}
			if err := w.once(ctx); err != nil {
				w.recordError(fmt.Errorf("poll: %w", err))
				log.Printf("[%s] poll: %v", w.harnessID, err)
				w.reRegisterAfterCoordinatorRestart(ctx, err)
			}
		}
		select {
		case <-ctx.Done():
			return
		case <-ticker.C:
		}
	}
}

// federatedTurn is the worker half of a turn boundary. The coordinator
// reconciles human input and answers with the decisions this session has not
// been shown; the worker delivers them into its own pane.
//
// Nothing is preempted. The boundary is confirmed against the live pane
// first, so a correction never lands mid tool call.
func (w *worker) federatedTurn(ctx context.Context, id string, a herdr.Adapter, verdict string) {
	l, ok := w.leases[id]
	if !ok {
		return
	}
	s, ok := w.sessions[id]
	if !ok {
		return
	}
	boundary, ok := a.(herdr.TurnBoundary)
	if !ok {
		return
	}
	at, err := boundary.AtTurnBoundary(ctx, s)
	if err != nil {
		w.recordError(fmt.Errorf("turn boundary %s: %w", id, err))
		return
	}
	if !at {
		return
	}
	// A phase this session no longer runs ends it, whether this worker asked
	// for the change or an operator made it (F22). Checked before the request
	// below so a session cannot advance a phase twice.
	if w.phaseChanged(id, s) {
		w.rotateForPhase(ctx, id, a, s)
		return
	}
	// A contradiction outranks both requests below. An implementer that has
	// found the plan wrong should not verify a phase of it or ask to leave the
	// phase; Orchestra decides what happens to the plan first.
	if w.reportPlanMismatch(ctx, id, s) {
		w.rotateForPhase(ctx, id, a, s)
		return
	}
	// A plan phase asks to be verified before the work phase asks to move.
	// Checked first because verifying the last phase is usually what makes a
	// session ready to leave implement at all, and this session keeps running
	// either way: verification is progress within a phase, not a change of one.
	if w.requestPlanVerification(ctx, id, s) {
		return
	}
	// The agent asks for a phase change here, at a boundary it has reached
	// (F21). Orchestra decides, and an accepted change ends this session.
	if w.requestPhase(ctx, id, s) {
		w.rotateForPhase(ctx, id, a, s)
		return
	}
	answer, err := w.api.Turn(ctx, id, l.Epoch, verdict, s.DeliveredDecisions)
	if err != nil {
		// Observable, not fatal. A coordinator that cannot be reached does not
		// make this session's current intent any more stale than it already is.
		w.recordError(fmt.Errorf("federated turn %s: %w", id, err))
		return
	}
	if answer.Verdict == orchestrator.TurnPrepareHandoff && !s.HandoffRequested {
		// The coordinator has lost the ability to refresh this task's intent.
		// Ask for a handoff; the release loop takes over as soon as the agent
		// writes the report, exactly as it does for a local session.
		requester, ok := a.(herdr.ReasonedHandoffRequester)
		if !ok {
			w.recordError(fmt.Errorf("reconcile failure handoff %s: adapter cannot state a reason", id))
			return
		}
		if err := requester.RequestHandoffReason(ctx, s, "reconcile_failure", nil); err != nil {
			w.recordError(fmt.Errorf("reconcile failure handoff %s: %w", id, err))
			return
		}
		s.HandoffRequested, s.HandoffReason = true, "reconcile_failure"
		w.sessions[id] = s
		_ = w.save()
		return
	}
	if len(answer.Decisions) == 0 {
		return
	}
	if err := w.sendPrompt(ctx, s, agentctx.DecisionNotice(answer.Decisions)); err != nil {
		// Not recorded as delivered, so the next boundary retries.
		w.recordError(fmt.Errorf("deliver decisions %s: %w", id, err))
		return
	}
	for _, d := range answer.Decisions {
		s.DeliveredDecisions = append(s.DeliveredDecisions, d.ID)
	}
	w.sessions[id] = s
	_ = w.save()
}

// phaseRequestFile is the agent's bounded phase-change intent (F21). Prose in
// the pane is not a request: matching on it would make the protocol depend on
// wording the agent is free to vary, and on Orchestra reading its own echo.
const phaseRequestFile = "phase-request.json"

// phaseRequest is what the agent writes. It states the phase it believes it
// is in as well as the one it wants, so a request written from a stale
// context is refused rather than applied to whatever phase is current.
type phaseRequest struct {
	From domain.WorkPhase `json:"from"`
	To   domain.WorkPhase `json:"to"`
}

// phaseArtifact names the sealed output each phase must produce before it may
// be left. Phases absent from this table seal nothing.
var phaseArtifact = map[domain.WorkPhase]string{
	domain.WorkPhaseResearch: "research.json",
	domain.WorkPhasePlan:     "plan.md",
}

func currentPhase(t domain.Task) domain.WorkPhase {
	if t.WorkPhase == "" {
		return domain.WorkPhaseFrame
	}
	return t.WorkPhase
}

// phaseChanged reports whether this session is running a phase the task has
// since left. It covers a change this worker requested and one an operator
// made through the coordinator equally, because both leave the same evidence:
// a session whose context was built for a phase that is no longer current.
func (w *worker) phaseChanged(id string, s herdr.Session) bool {
	t, ok := w.tasks[id]
	if !ok || s.Phase == "" {
		return false
	}
	return string(currentPhase(t)) != s.Phase
}

// rotateForPhase ends the current cognitive session because the phase moved
// (F22). A phase change is a change of context, not of instruction: leaving
// the old agent running would either waste the lease waiting for it to idle
// out, as run 3 did, or let it keep working under a brief that no longer
// applies.
func (w *worker) rotateForPhase(ctx context.Context, id string, a herdr.Adapter, s herdr.Session) {
	if s.HandoffRequested {
		return
	}
	requester, ok := a.(herdr.ReasonedHandoffRequester)
	if !ok {
		w.recordError(fmt.Errorf("phase rotation %s: adapter cannot state a reason", id))
		return
	}
	if err := requester.RequestHandoffReason(ctx, s, "phase_changed", nil); err != nil {
		w.recordError(fmt.Errorf("phase rotation %s: %w", id, err))
		return
	}
	s.HandoffRequested, s.HandoffReason = true, "phase_changed"
	w.sessions[id] = s
	_ = w.save()
	log.Printf("phase changed for %s: session rotating", id)
}

// answerRefusedPhase tells the agent why its request was refused and drops the
// file so it can write a corrected one. The request survives a failed send, so
// the refusal is delivered at the next boundary instead of being lost.
func (w *worker) answerRefusedPhase(ctx context.Context, id string, s herdr.Session, path, reason string) {
	text := "Orchestra refused your phase request: " + reason +
		"\n\nWrite a corrected .orchestra/phase-request.json, or keep working in the current phase. Do not repeat the refused request."
	if err := w.sendPrompt(ctx, s, text); err != nil {
		w.recordError(fmt.Errorf("deliver phase refusal %s: %w", id, err))
		return
	}
	if err := os.Remove(path); err != nil {
		w.recordError(fmt.Errorf("phase request %s: %w", id, err))
	}
	log.Printf("phase request %s refused: %s", id, reason)
}

// requestPhase carries an agent's phase request to the coordinator (F21).
// It reports whether the phase moved.
//
// Everything checkable locally is checked before the call, so an agent that
// asked for the wrong thing learns it from a recorded error rather than from
// a lease that quietly stops being renewed.
func (w *worker) requestPhase(ctx context.Context, id string, s herdr.Session) bool {
	path := filepath.Join(s.Worktree, ".orchestra", phaseRequestFile)
	b, err := os.ReadFile(path)
	if err != nil {
		return false
	}
	var req phaseRequest
	if err := json.Unmarshal(b, &req); err != nil {
		w.recordError(fmt.Errorf("phase request %s: %w", id, err))
		return false
	}
	t, ok := w.tasks[id]
	if !ok {
		return false
	}
	if req.From != currentPhase(t) {
		w.recordError(fmt.Errorf("phase request %s: task is in work phase %q, not %q", id, currentPhase(t), req.From))
		return false
	}
	if !domain.CanTransitionPhase(req.From, req.To) {
		w.recordError(fmt.Errorf("phase request %s: %q to %q is not a legal transition", id, req.From, req.To))
		return false
	}
	// The phase being left seals its result before it may be left. Decoding
	// here means a malformed artifact is reported against the agent that
	// wrote it, while its session is still alive to be told.
	var artifact []byte
	if name := phaseArtifact[req.From]; name != "" {
		artifact, err = os.ReadFile(filepath.Join(s.Worktree, ".orchestra", name))
		if err != nil {
			w.recordError(fmt.Errorf("phase request %s: work phase %q must seal .orchestra/%s first: %w", id, req.From, name, err))
			w.answerRefusedPhase(ctx, id, s, path, fmt.Sprintf("work phase %q must seal .orchestra/%s first: %v", req.From, name, err))
			return false
		}
		var decErr error
		switch req.From {
		case domain.WorkPhaseResearch:
			_, decErr = workphase.DecodeResearch(artifact)
		case domain.WorkPhasePlan:
			// A new seal is markdown. The coordinator re-parses and also
			// resolves research citations, which the worker cannot check
			// because it does not hold the accepted research.
			_, decErr = workphase.ParsePlan(artifact)
		}
		if decErr != nil {
			w.recordError(fmt.Errorf("phase request %s: %s artifact: %w", id, req.From, decErr))
			// A local refusal is still a refusal, and the agent is the only
			// party that can fix it. Recording it in worker health alone left
			// a live session parked at a boundary forever with nothing telling
			// it what was wrong (F39) — the silent-loop shape the comment
			// above this block warns about, reached by the one path that had
			// no delivery.
			w.answerRefusedPhase(ctx, id, s, path, fmt.Sprintf(".orchestra/%s does not match the schema: %v", name, decErr))
			return false
		}
	}
	l := w.leases[id]
	// Derived, not random: a redelivery after a lost response must carry the
	// same id so the coordinator recognises it instead of advancing twice.
	op := "phase:" + id + ":" + l.Epoch + ":" + string(req.From) + ":" + string(req.To)
	phase, err := w.api.AdvancePhase(ctx, id, l.Epoch, op, req.From, req.To, artifact)
	if err != nil {
		w.recordError(fmt.Errorf("phase request %s: %w", id, err))
		// A refusal is an answer, and it names the phase the agent may ask
		// for. Recording it only in worker health would leave the agent
		// rewriting the same rejected file at every boundary with nothing
		// telling it why, which is the silent-loop shape this codebase keeps
		// producing. A transport failure is not an answer and is retried.
		var status *federation.StatusError
		if errors.As(err, &status) && status.Code == http.StatusConflict {
			w.answerRefusedPhase(ctx, id, s, path, status.Body)
		}
		return false
	}
	if phase == "" {
		// Accepted but not advanced: the coordinator raised a trajectory gate
		// and the human now owns the move. Keep the request so the same ask is
		// re-sent, under the same operation id, once the gate clears.
		return false
	}
	// Durable before the file is removed. A removal that raced the response
	// would lose the request and leave the agent waiting on an answer that
	// already arrived.
	if err := os.Remove(path); err != nil {
		w.recordError(fmt.Errorf("phase request %s: %w", id, err))
	}
	if phase == domain.WorkPhaseReview {
		// Each entry into review starts without the previous cycle's findings.
		// The worktree survives a changes-requested round trip, so a reviewer
		// that writes .orchestra/done without rewriting the file would have
		// the earlier review sealed against the new commit — and submit binds
		// whatever it reads to the commit it is submitting, so a stale pass
		// would look exactly like a fresh one.
		if err := os.Remove(filepath.Join(s.Worktree, ".orchestra", reviewFile)); err != nil && !os.IsNotExist(err) {
			w.recordError(fmt.Errorf("clear stale review %s: %w", id, err))
		}
	}
	t.WorkPhase = phase
	w.tasks[id] = t
	log.Printf("phase request %s accepted: %s to %s", id, req.From, phase)
	return true
}

// sendPrompt delivers Orchestra-originated input and confirms the harness took
// it. A phase continuation or a decision notice whose Enter is lost strands the
// session exactly as a lost launch does.
func (w *worker) sendPrompt(ctx context.Context, s herdr.Session, text string) error {
	backend := w.executionBackend()
	if backend == nil {
		return fmt.Errorf("execution backend is not configured")
	}
	if err := backend.Prompt(ctx, s.PaneID, text, time.Minute); err != nil {
		return err
	}
	return w.confirmInput(ctx, s, text)
}

// confirmInput is the one place Orchestra proves a write landed. A backend
// whose own protocol acknowledges input does not implement InputConfirmer and
// needs no second opinion.
func (w *worker) confirmInput(ctx context.Context, s herdr.Session, text string) error {
	c, ok := w.executionBackend().(herdr.InputConfirmer)
	if !ok {
		return nil
	}
	evidence, err := c.ConfirmInput(ctx, s, text)
	if err != nil {
		return err
	}
	log.Printf("input to %s confirmed: %s", s.PaneID, evidence)
	return nil
}

// paneProgress reports pane content with input lines removed where the backend
// can separate them, and falls back to the raw capture where it cannot.
func (w *worker) paneProgress(ctx context.Context, adapter herdr.CLIAdapter, s herdr.Session) (string, error) {
	if p, ok := w.executionBackend().(herdr.PaneProgress); ok {
		return p.PaneProgress(ctx, s)
	}
	return adapter.PaneCapture(ctx, s, "recent")
}

// planProgressFile is the implementer's bounded verification request. It
// carries one phase and one status, and the only status it may carry is a
// request: an agent that could write "verified" would be marking its own work
// done, which is the whole thing this machinery exists to prevent.
const planProgressFile = "plan-progress.json"

type planProgressRequest struct {
	Phase  string `json:"phase"`
	Status string `json:"status"`
}

// requestPlanVerification runs one phase's automated checks and posts the
// results. It reports whether anything was done, so the caller does not treat
// an absent request as a failure.
//
// The commands come from the accepted plan, which the coordinator resolves and
// authorises. This worker never reads a command out of the request: the
// request names a phase, and nothing else about it is trusted.
func (w *worker) requestPlanVerification(ctx context.Context, id string, s herdr.Session) bool {
	path := filepath.Join(s.Worktree, ".orchestra", planProgressFile)
	b, err := os.ReadFile(path)
	if err != nil {
		return false
	}
	var req planProgressRequest
	if err := json.Unmarshal(b, &req); err != nil {
		w.answerRefusedProgress(ctx, id, s, path, fmt.Sprintf(".orchestra/%s is not valid JSON: %v", planProgressFile, err))
		return false
	}
	if req.Status != domain.PlanPhaseRequestStatus {
		// Naming this refusal precisely matters: an agent that wrote
		// "verified" is trying to establish a fact, and it has to learn that
		// establishing facts is not its job rather than retry the same file.
		w.answerRefusedProgress(ctx, id, s, path, fmt.Sprintf("status %q is not writable by you. The only status you may request is %q; Orchestra decides the rest by running the plan's own commands.", req.Status, domain.PlanPhaseRequestStatus))
		return false
	}
	l := w.leases[id]
	commands, err := w.api.PlanPhaseCommands(ctx, id, req.Phase, l.Epoch)
	if err != nil {
		// A refusal is an answer and reaches the agent. A transport failure is
		// not, and the request survives for the next boundary.
		var status *federation.StatusError
		if errors.As(err, &status) && status.Code == http.StatusConflict {
			w.answerRefusedProgress(ctx, id, s, path, status.Body)
			return false
		}
		w.recordError(fmt.Errorf("plan verification %s: %w", id, err))
		return false
	}
	head, err := git(ctx, s.Worktree, "rev-parse", "HEAD")
	if err != nil {
		w.recordError(fmt.Errorf("plan verification %s: head: %s: %w", id, head, err))
		return false
	}
	runs := make([]federation.VerificationRun, 0, len(commands))
	for _, argv := range commands {
		// No shell. The quality gate's envelope is exec in the worktree, and a
		// plan command is agent-authored, so it gets that envelope and never a
		// weaker one. A pipe here is a literal argument.
		cmd := exec.CommandContext(ctx, argv[0], argv[1:]...)
		cmd.Dir = s.Worktree
		out, runErr := cmd.CombinedOutput()
		code := 0
		if runErr != nil {
			code = 1
			var exit *exec.ExitError
			if errors.As(runErr, &exit) {
				code = exit.ExitCode()
			}
		}
		runs = append(runs, federation.VerificationRun{Command: argv, ExitCode: code, Output: tail(string(out), review.MaxGateOutputBytes)})
	}
	status, err := w.api.RecordPlanPhase(ctx, id, req.Phase, strings.TrimSpace(string(head)), l.Epoch, runs)
	if err != nil {
		w.recordError(fmt.Errorf("plan verification %s: %w", id, err))
		return false
	}
	// Durable before the request is removed. Removing first would lose the
	// request if the response were lost, and the agent would wait on an answer
	// that already happened.
	if err := os.Remove(path); err != nil {
		w.recordError(fmt.Errorf("plan verification %s: %w", id, err))
	}
	w.tellProgressOutcome(ctx, id, s, req.Phase, status, runs)
	return true
}

// tellProgressOutcome delivers what Orchestra established. A phase that did
// not verify is the case that matters: without this the agent sees a request
// disappear and has to guess whether it worked.
func (w *worker) tellProgressOutcome(ctx context.Context, id string, s herdr.Session, phase, status string, runs []federation.VerificationRun) {
	var b strings.Builder
	switch status {
	case string(domain.PlanPhaseVerified):
		fmt.Fprintf(&b, "Orchestra verified %s. Every automated check passed. Move to the next phase of the plan.", phase)
	case string(domain.PlanPhaseAwaitingManual):
		fmt.Fprintf(&b, "Orchestra ran %s's automated checks and they passed. The phase is waiting for the human to confirm its manual steps, which you cannot do. Continue with the next phase; the sign-off arrives on its own.", phase)
	default:
		fmt.Fprintf(&b, "Orchestra ran %s's checks and it is not verified. Fix what failed, then write .orchestra/%s again.\n", phase, planProgressFile)
		for _, r := range runs {
			if r.ExitCode == 0 {
				continue
			}
			fmt.Fprintf(&b, "\n%s exited %d:\n%s\n", strings.Join(r.Command, " "), r.ExitCode, r.Output)
		}
	}
	if err := w.sendPrompt(ctx, s, b.String()); err != nil {
		w.recordError(fmt.Errorf("deliver plan verification %s: %w", id, err))
	}
	log.Printf("plan phase %s of %s: %s", phase, id, status)
}

// answerRefusedProgress tells the implementer why its request was refused and
// drops the file so a corrected one can be written. Recording a refusal only
// in worker health leaves a live session rewriting the same rejected file at
// every boundary, which is the silent-loop shape this codebase keeps producing
// (F39, F42, and the completion tail).
func (w *worker) answerRefusedProgress(ctx context.Context, id string, s herdr.Session, path, reason string) {
	w.recordError(fmt.Errorf("plan verification %s refused: %s", id, reason))
	text := "Orchestra refused your verification request: " + reason +
		"\n\nWrite a corrected .orchestra/" + planProgressFile + ", or keep working. Do not repeat the refused request."
	if err := w.sendPrompt(ctx, s, text); err != nil {
		w.recordError(fmt.Errorf("deliver plan verification refusal %s: %w", id, err))
		return
	}
	if err := os.Remove(path); err != nil {
		w.recordError(fmt.Errorf("plan verification %s: %w", id, err))
	}
	log.Printf("plan verification %s refused: %s", id, reason)
}

// planMismatchFile is the implementer's bounded report that the accepted plan
// is contradicted by the code. It carries an observation, never a replacement
// plan: writing the next plan is the planning phase's work, and an implementer
// that could supply one would be planning from inside the phase meant to
// execute a plan.
const planMismatchFile = "plan-mismatch.json"

// reportPlanMismatch carries the report to the coordinator, which decides
// whether to reopen planning, reopen research, or stop for the human. It
// reports whether the phase moved, because an accepted reopen ends this
// session exactly as an accepted phase request does.
func (w *worker) reportPlanMismatch(ctx context.Context, id string, s herdr.Session) bool {
	path := filepath.Join(s.Worktree, ".orchestra", planMismatchFile)
	b, err := os.ReadFile(path)
	if err != nil {
		return false
	}
	var m domain.PlanMismatch
	if err := json.Unmarshal(b, &m); err != nil {
		w.answerRefusedMismatch(ctx, id, s, path, fmt.Sprintf(".orchestra/%s is not valid JSON: %v", planMismatchFile, err))
		return false
	}
	t, ok := w.tasks[id]
	if !ok {
		return false
	}
	// Both bindings are filled from what this worker can verify, not from what
	// the agent wrote. A report is about the plan the task actually works from
	// and the tree it actually has; letting the agent state either would make
	// the staleness check meaningless.
	m.PlanRef = t.PlanRef
	head, err := git(ctx, s.Worktree, "rev-parse", "HEAD")
	if err != nil {
		w.recordError(fmt.Errorf("plan mismatch %s: head: %s: %w", id, head, err))
		return false
	}
	m.AtSHA = strings.TrimSpace(string(head))
	if err := m.Validate(); err != nil {
		w.answerRefusedMismatch(ctx, id, s, path, err.Error())
		return false
	}
	l := w.leases[id]
	phase, err := w.api.ReportPlanMismatch(ctx, id, l.Epoch, m)
	if err != nil {
		var status *federation.StatusError
		if errors.As(err, &status) && status.Code == http.StatusConflict {
			w.answerRefusedMismatch(ctx, id, s, path, status.Body)
			return false
		}
		w.recordError(fmt.Errorf("plan mismatch %s: %w", id, err))
		return false
	}
	// Durable before the file goes. A removal that raced the response would
	// lose the report and leave the agent waiting on an answer that arrived.
	if err := os.Remove(path); err != nil {
		w.recordError(fmt.Errorf("plan mismatch %s: %w", id, err))
	}
	if phase == "" {
		// Recorded, and the task stopped for the human. The session ends: the
		// contradiction it found is now someone else's to resolve.
		log.Printf("plan mismatch %s: blocked for the human", id)
		return true
	}
	t.WorkPhase = domain.WorkPhase(phase)
	w.tasks[id] = t
	log.Printf("plan mismatch %s: reopened %s", id, phase)
	return true
}

// answerRefusedMismatch tells the implementer why its report was refused. A
// stale report is the common case, and the agent has to learn that rather than
// rewrite the same rejected file at every boundary.
func (w *worker) answerRefusedMismatch(ctx context.Context, id string, s herdr.Session, path, reason string) {
	w.recordError(fmt.Errorf("plan mismatch %s refused: %s", id, reason))
	text := "Orchestra refused your plan mismatch report: " + reason +
		"\n\nA report needs observed, contradicts, the phase id, and requested_action of replan, research, or human_decision. Do not propose a replacement plan: that is the planning phase's work. Write a corrected .orchestra/" + planMismatchFile + ", or keep working."
	if err := w.sendPrompt(ctx, s, text); err != nil {
		w.recordError(fmt.Errorf("deliver plan mismatch refusal %s: %w", id, err))
		return
	}
	if err := os.Remove(path); err != nil {
		w.recordError(fmt.Errorf("plan mismatch %s: %w", id, err))
	}
	log.Printf("plan mismatch %s refused: %s", id, reason)
}