wip(freestyle/acr): grounding & edit-tool fixes + ACR-compiler experiment

This branch's uncommitted WIP, committed together (entangled at file level).
Distinct pieces of work:

Freestyle QA fixes (this session):
- FileEditTool: pre-validate replace anchor in validateRequest — reject a
  missing/ambiguous target BEFORE the approval gate, mirroring read/write's
  file-not-found / read-before-write pre-checks. Shared not-found/ambiguous
  messages between validate and execute so they can't drift.
- PlanGrounder: add `scanned` flag; when no RepoMapComputedEvent was recorded,
  repoMapPaths is "unknown" not "empty workspace" — skip scope grounding
  (which proves a path ABSENT) so real paths (apps/server/**) aren't falsely
  rejected. Build-manifest check still runs.
- FreestyleDriver: wire scanned=(repoMap!=null); on plan rejection emit a
  session-terminal WorkflowFailedEvent so a rejected run reads FAILED, not the
  COMPLETED-lie (last verdict was the planning-phase WorkflowCompleted).
- ServerModule: resolve project-memory workspace root from the session's bound
  workspace (sessionWorkspaceRoot) instead of boot-static pm.repoRoot(), fixing
  the workspace-binding divergence (correx vs empty scratch dir). Retire tracked
  in Vikunja #266.
- LaunchRegistrationRaceTest: join registered jobs before asserting launchCount
  — computeIfAbsent returns the Job immediately but the fire-and-forget launch
  body lagged awaitAll (the 49-vs-50 flake).

ACR concept-compiler experiment (pre-existing WIP on this branch):
- ExecutionPlanCompiler/Model/PlanLinter, #264 needs-seam (sessionArtifacts),
  LSP diagnostics subsystem (LspDiagnosticEvents/Runner/Lsp4j), BootWorkspace,
  config surface, workflow prompts/schemas, orchestrator advance-don't-rerun.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

core/kernel/AGENTS.md

@@ -19,6 +19,8 @@ CORREX kernel team. This is the integration point for all other `core/` modules.
 - `ReplayOrchestrator` / `ReplayInferenceProvider` / `ReplayStrategy` — deterministic replay of a session from its event log. `ReplayInferenceProvider` returns recorded responses — no live LLM (Hard Invariant #8).
 - `SubagentRunner` / `InSessionSubagentRunner` — runs sub-agent invocations within an active session.
 - `StaticAnalysisRunner` / `ProcessStaticAnalysisRunner` — runs static analysis tools and records results as events.
+- `LspDiagnosticsRunner` — injected pull-diagnostics seam; diagnostics are filtered to stage-written files, recorded, and enforced before build/review.
+- Review→rework loops use the configured three-cycle default, then route accumulated notes to recovery once and fail if the fixed DoD still cannot be approved.
 - `StageCheckpointReconciler` — reconciles checkpoint state across stage transitions.
 - Capability-gated failures first retry in place when the stage holds the required tool; an unchanged-fingerprint gate-budget exhaustion routes to the recovery/intent-holder stage when one is available, so capability possession alone cannot cause a frozen owner loop to fail the workflow.
 - Three repeated `REFERENCE_EXISTS` blocks for the same build prerequisite within one stage become a `workspace_precondition` gate failure, which is eligible for file-write recovery rather than remaining disconnected tool-call noise.