feat: Docker, health check, schema migrations y webhook opt-in

- migrations/001_initial_schema.sql: DDL idempotente con CREATE TABLE/INDEX IF NOT EXISTS
- database.py: run_migrations() aplica .sql pendientes en orden; init_db() queda como alias
- health.py: servidor aiohttp en puerto 8080 — GET /health, GET /health/history, POST /webhook
  Watcher loop alerta al admin por Telegram si el poller no actualiza en N horas
- config.py: webhook_url, webhook_secret, health_port, health_alert_hours
- poller.py: on_poll_done callback (conecta con health.record_poll)
- main.py: arranca HealthServer, llama run_migrations, modo webhook opt-in via WEBHOOK_URL
- Dockerfile + docker-compose.yml + .dockerignore
- pyproject.toml: aiohttp>=3.9

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

docker-compose.yml

@@ -0,0 +1,20 @@
+services:
+  pedrito:
+    build: .
+    restart: unless-stopped
+    env_file: .env
+    ports:
+      - "8080:8080"    # health check (y webhook si está configurado)
+    volumes:
+      - ./data:/app/data    # snapshot y DB persistentes entre reinicios
+    healthcheck:
+      test: ["CMD", "curl", "-sf", "http://localhost:8080/health"]
+      interval: 60s
+      timeout: 5s
+      retries: 3
+      start_period: 15s
+    logging:
+      driver: "json-file"
+      options:
+        max-size: "10m"
+        max-file: "3"