feat: wire configured harness execution

internal/orchestrator/orchestrator.go

@@ -10,6 +10,9 @@ import (
 	"orchestra/internal/domain"
 	"orchestra/internal/herdr"
 	"orchestra/internal/store"
+	"os"
+	"os/exec"
+	"path/filepath"
 	"sync"
 )
 
@@ -20,6 +23,43 @@ type Adapters interface {
 	Adapter(string) (herdr.Adapter, error)
 }
 
+// GitWorktrees creates one isolated checkout per task. The root is expected
+// to be a clone containing the project's remote; callers may set a separate
+// root per deployment.
+type GitWorktrees struct {
+	Root string
+	Repo string
+}
+
+func (w GitWorktrees) Create(ctx context.Context, t domain.Task) (string, error) {
+	if w.Root == "" || w.Repo == "" {
+		return "", fmt.Errorf("worktree: root and repo required")
+	}
+	if err := os.MkdirAll(w.Root, 0755); err != nil {
+		return "", err
+	}
+	p := filepath.Join(w.Root, t.ID)
+	if _, err := os.Stat(p); err == nil {
+		return p, nil
+	}
+	branch := "orchestra/" + t.ID
+	cmd := exec.CommandContext(ctx, "git", "-C", w.Repo, "worktree", "add", "-b", branch, p, "HEAD")
+	if out, err := cmd.CombinedOutput(); err != nil {
+		return "", fmt.Errorf("%s: %w", string(out), err)
+	}
+	return p, nil
+}
+
+type AdapterFactory struct{ Herdrs map[string]herdr.Adapter }
+
+func (f AdapterFactory) Adapter(id string) (herdr.Adapter, error) {
+	a, ok := f.Herdrs[id]
+	if !ok {
+		return nil, fmt.Errorf("adapter %q not registered", id)
+	}
+	return a, nil
+}
+
 type Coordinator struct {
 	Store     *store.Store
 	Worktrees Worktrees