feat: add Docker health check and post-deploy verification

[nickmeinhold]

Problem or Motivation

Current deploy verification only checks if the container status is "running" — it doesn't verify the app inside is actually healthy (bot connected to Telegram, MCP servers initialized, DB migrated). A container can be "running" but the app inside crashed and is in a restart loop.

Proposed Solution

1. Health check endpoint — add a simple HTTP health server (e.g., on port 8080) that reports:

   • Bot connected to Telegram (polling active)
   • MCP manager initialized
   • DB accessible
   • Last successful message timestamp

2. Docker HEALTHCHECK — add to Dockerfile:

   HEALTHCHECK --interval=10s --timeout=3s --retries=3 \
     CMD curl -f http://localhost:8080/health || exit 1

3. Deploy verification upgrade — check health endpoint instead of just container status

4. Version endpoint — expose current version from package.json at /version for deployment tracking

Acceptance Criteria

• HTTP health server runs alongside bot on configurable port
• /health returns JSON with component status
• /version returns current version and git SHA
• Dockerfile includes HEALTHCHECK
• Deploy workflow checks health endpoint
• Health check doesn't interfere with bot operation