Phase 4 (Performance) + Phase 6 (Infrastructure) completion

Phase 4 — Performance:
- F1: SSH DialPool with key-by-host pooling and 5min idle TTL
- F2: In-memory entity lookup cache (TTL 60s, HTTP resolveEntityID)
- F3: Trigram GIN indexes on entities.slug and entities.name (migration 031)
- F4: Partial index on executions(classification_id) for auto-act (migration 032)
- Added missing RunOutput and RunStreaming in actuator/ (E3 gap fill)

Phase 6 — Infrastructure:
- H1: Infisical image pinned to v0.99.1
- H2: execworker daemon — polls pending executions with per-execution
  advisory locks, recovers orphaned running executions, wired as
  docker-compose service
- H3: splitSQL hardened with block comment and string-literal support,
  6 new edge-case tests (11 total)
- H4: Scheduler acquires pg_try_advisory_lock(0x01c05e6) at startup

docker-compose.yml

@@ -195,6 +195,37 @@ services:
       retries: 3
       start_period: 120s
 
+  # Execution worker (Phase 6) — Postgres-backed job queue
+  execution-worker:
+    image: oikos-execution-worker:${OIKOS_VERSION:-latest}
+    build:
+      context: .
+      dockerfile: compose/oikos/Dockerfile
+    restart: unless-stopped
+    profiles: ["dev", "full"]
+    depends_on:
+      seed:
+        condition: service_completed_successfully
+    environment:
+      OIKOS_DATABASE_URL: postgres://oikos:${OIKOS_DB_PASSWORD:-oikos_dev}@postgres:5432/oikos?sslmode=disable
+      OIKOS_DEBUG: "true"
+      OIKOS_SSH_KEY_PATH: /etc/oikos/ssh_key
+      OIKOS_SSH_USER: root
+      OIKOS_HEALTH_LISTEN: ":8095"
+    volumes:
+      - ${OIKOS_SSH_KEY_PATH:-~/.ssh/id_ed25519}:/etc/oikos/ssh_key:ro
+    command: ["execution-worker"]
+    stop_signal: SIGTERM
+    stop_grace_period: 30s
+    mem_limit: 256m
+    cpus: 1.0
+    healthcheck:
+      test: ["CMD", "wget", "-q", "-O", "-", "http://127.0.0.1:8095/healthz"]
+      interval: 30s
+      timeout: 5s
+      retries: 3
+      start_period: 90s
+
   # Nomos agent gateway (Phase 4) — mesh-published :8092
   nomos:
     image: oikos-nomos:${OIKOS_VERSION:-latest}
@@ -276,7 +307,7 @@ services:
 
   # Infisical self-hosted (Phase 5 secrets management)
   infisical:
-    image: infisical/infisical:latest
+    image: infisical/infisical:v0.99.1
     restart: unless-stopped
     profiles: ["infisical", "full"]
     depends_on: