phase 3: control loop — scheduler, actuator, learning, notifier, policy, API endpoints

Implemented the full OODA control loop:

Scheduler:
- Check_defs runner with bounded worker pool (errgroup)
- Signal dedup via partial unique index (UpsertSignal)
- Recovery auto-resolves open signals
- Metrics writing (InsertMetricSample) and entity_status updates
- Housekeeping (idempotency-key prune)
- Graceful shutdown via ctx cancellation

Actuator:
- Auto-act signal consumer with FOR UPDATE SKIP LOCKED pattern
- Per-target serialization with pg_advisory_xact_lock
- Circuit breaker per target host (N consecutive failures → open)
- Autonomy kill-switch (global.auto_act, never_auto_act.<slug>)
- Execution record lifecycle (proposed → running → completed)

Learning engine:
- Hourly feedback extraction past watermark
- Wilson score confidence lower bound (conservative for small N)
- Pattern status: hypothesized → validated (N≥5, confidence ≥0.7)
- Anomaly quarantine for burst feedback
- Cap confidence by sample_size/5 (nothing confident before 5 samples)

Notifier:
- Approval token generation (HMAC single-use, hashed at rest)
- Pending approval expiry detection
- DB rendezvous pattern (no service-to-service RPC)

Policy classifier:
- Risk class resolution from policy tables
- Autonomy checks (global + per-entity kill-switch)
- Blast radius computation
- Classification routes: auto-act / escalate / hold

API endpoints (31 endpoints implemented):
- Checks: ListChecks, CreateCheck, PatchCheck
- Classifications: ListClassifications
- Executions: ListExecutions, GetExecution, RequestExecution, CancelExecution
- Approvals: ListApprovals, DecideApproval
- Patterns: ListPatterns, PatchPattern
- Skills: ListSkills, PatchSkill, ListSkillVersions
- Policy: ListApprovalRules, CreateApprovalRule, PatchApprovalRule,
  GetAutonomySettings, PatchAutonomySettings, ListRiskClasses
- Relationships: CreateRelationship, EndRelationship
- Entity types: CreateEntityType, PatchEntityType
- Metrics: QueryMetrics, GetTrends
- Knowledge: SearchKnowledge, GetEntityKnowledge (stubs)
- Agent activity: QueryAgentActivity (stub)

Infrastructure:
- Migration 009: knowledge_entities table with FTS indexes
- Config: scheduler/notifier/actuator/learning env vars
- sqlc: 30+ new Phase 3 queries
- Integration tests for all new endpoints
- go.sum updated with golang.org/x/sync

migrations/009_knowledge.up.sql

@@ -0,0 +1,15 @@
+-- Migration 009: Knowledge entities (FTS search for documentation)
+-- Creates the knowledge_entities table for Phase 3 search/knowledge endpoints.
+
+CREATE TABLE IF NOT EXISTS knowledge_entities (
+    entity_id   UUID PRIMARY KEY REFERENCES entities(id),
+    title       TEXT NOT NULL,
+    content     TEXT NOT NULL,
+    source      TEXT,
+    tags        TEXT[],
+    created_at  TIMESTAMPTZ NOT NULL DEFAULT now(),
+    updated_at  TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+
+CREATE INDEX idx_knowledge_title ON knowledge_entities USING gin(to_tsvector('english', title));
+CREATE INDEX idx_knowledge_content ON knowledge_entities USING gin(to_tsvector('english', content));