feat: implement proper orchestrator workflow with reconciliation loop

Rewrite OrchestratorWorkflow as true reconciliation loop:
- PlanningActivity decides what tasks to dispatch
- Fan-out TaskUnit workflows for parallel execution
- Each TaskUnit runs Implementer → Test → Judge → Commit
- Judge reviews code quality, retries on failure with lessons
- Fan-in waits for all TaskUnits
- Board update and squash merge on success
- continue-as-new for long-running workflows
- Proper error handling and signal support

Key changes:
- statemachine/orchestrator.go: Reconciliation loop (Plan → Dispatch → Review → Repeat)
- statemachine/taskunit.go: Task execution with retry loop & judge review
- statemachine/types.go: Updated TaskUnitInput/Output for new workflow
- cmd/worker/main.go: Register RunIntegrationTestActivity
- action/integration.go: Renamed from integration_test.go (fix Go build issue)

Models:
- Planner: reasoning (OpenAI-compatible from local LLM API)
- Judge: reasoning (reviews diff + tests, gates success)
- Implementer: ornith:35b (executes tasks)

Verification: go build ./cmd/worker ./cmd/starter ✓

k8s/git-commit.yaml

@@ -9,6 +9,6 @@ metadata:
     app.kubernetes.io/name: poimen
     app.kubernetes.io/component: orchestrator
 data:
-  GIT_COMMIT: "0b6bca7"  # Updated automatically by CI/CD
+  GIT_COMMIT: "9fb58ae"  # Updated automatically by CI/CD
   GIT_BRANCH: "main"
   DEPLOYMENT_DATE: "2026-08-26"