feat: add Orchestrator Loop — phased plan execution with team agents

Adds a new autonomous loop that accepts high-level goals, generates
phased execution plans via AI, and executes them step-by-step with
verification gates between phases.

Core components:
- OrchestratorLoop: state machine (idle→planning→approval→executing→verifying→completed)
- OrchestratorPlanner: plan generation via PlanOrchestrator, Kahn's algorithm phase grouping
- OrchestratorVerifier: phase verification (strict/moderate/lenient modes)
- Prompt templates for phase execution, team delegation, verification, replanning

API (10 endpoints):
- POST start/approve/reject/pause/resume/stop
- GET status/plan
- POST phase/:id/skip, phase/:id/retry

Frontend: orchestrator-panel.js with SSE-driven state, phase progress, task tracking

Tests: 22 tests (18 route + 4 unit), all passing. Typecheck/lint/format clean.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/web/public/constants.js

@@ -277,6 +277,19 @@ const SSE_EVENTS = {
   PLAN_STARTED: 'plan:started',
   PLAN_CANCELLED: 'plan:cancelled',
   PLAN_COMPLETED: 'plan:completed',
+
+  // Orchestrator Loop
+  ORCHESTRATOR_STATE_CHANGED: 'orchestrator:stateChanged',
+  ORCHESTRATOR_PLAN_READY: 'orchestrator:planReady',
+  ORCHESTRATOR_PHASE_STARTED: 'orchestrator:phaseStarted',
+  ORCHESTRATOR_PHASE_COMPLETED: 'orchestrator:phaseCompleted',
+  ORCHESTRATOR_PHASE_FAILED: 'orchestrator:phaseFailed',
+  ORCHESTRATOR_VERIFICATION: 'orchestrator:verification',
+  ORCHESTRATOR_TASK_ASSIGNED: 'orchestrator:taskAssigned',
+  ORCHESTRATOR_TASK_COMPLETED: 'orchestrator:taskCompleted',
+  ORCHESTRATOR_TASK_FAILED: 'orchestrator:taskFailed',
+  ORCHESTRATOR_COMPLETED: 'orchestrator:completed',
+  ORCHESTRATOR_ERROR: 'orchestrator:error',
 };
 
 // ═══════════════════════════════════════════════════════════════