feat: dedicated auto-healing agent — sidecar container + pi agent definition

- auto-healer/Dockerfile: lightweight Alpine container with Docker CLI
- auto-healer/auto-heal-agent.sh: real-time fault detection + remediation engine
  - Detects: crash, OOM, DB disconnect, gateway down, disk pressure
  - Fixes: restart, rollback, nginx reload, prune, escalate
  - Sliding window restart tracking (3/hr max)
- auto-healer/docker-compose.healer.yml: sidecar deployment config
  - Mounts Docker socket for event monitoring
  - Host network mode for health checks
  - Persistent state in /var/state/falah
- .pi/agents/auto-healer.md: pi agent definition for manual invocation

auto-healer/docker-compose.healer.yml

@@ -0,0 +1,26 @@
+version: "3.8"
+services:
+  falah-auto-healer:
+    build:
+      context: ./auto-healer
+      dockerfile: Dockerfile
+    image: falah-auto-healer:latest
+    container_name: falah-auto-healer
+    restart: unless-stopped
+    volumes:
+      - /var/run/docker.sock:/var/run/docker.sock:ro
+      - /var/log/falah:/var/log/falah
+      - /var/state/falah:/var/state/falah
+    environment:
+      - CONTAINER_NAME=falah-mobile-staging
+      - HEALTH_URL=http://192.168.0.11:4014/mobile/api/health
+      - GATEWAY_URL=http://192.168.0.11:7878/mobile/api/health
+      - CHECK_INTERVAL=30
+      - MAX_RESTARTS_PER_HOUR=3
+      - ROLLBACK_IMAGE=falah-mobile:rollback
+    network_mode: "host"
+    logging:
+      driver: "json-file"
+      options:
+        max-size: "10m"
+        max-file: "3"