Jetstream was running backgrounded in the same container as the API server,
so crashes went undetected and Docker never restarted it. Now each process
runs as a separate docker-compose service with independent restart policies.
Also adds cursor persistence to SQLite (saved every 5s) so restarts resume
from where they left off, moves event destructuring inside try/catch blocks,
and adds global unhandled error/rejection handlers for crash visibility.
Add Docker containerization with Deno and persistent SQLite volume.
Add GitLab CI pipeline with build and deploy stages.
Use SQLITE_PATH env var for configurable DB location.
