Part of Epic #269.
Add scripts/deploy_synapse.py — automated Synapse deployment:
- Checks prerequisites (Docker, docker-compose, curl)
- Auto-installs Docker if missing
- Deploys Synapse via Docker with generated homeserver.yaml
- Waits for health check
- Creates bot account (hermes-bot)
- Logs in and obtains access token
- Prints Hermes config (env vars) for easy copy-paste
- Supports --dry-run for safe testing
- 9 new tests
