chore(indexer): move Fly config to project root for correct build context
The Dockerfile expects to be built from the project root (it COPYs the
top-level worker/, lib/, lexicons/ folders). When fly.toml lived inside
worker/, flyctl deployed with worker/ as the build context, which broke
those COPYs.
Move both files up one level and rename so they're easy to spot next to
the existing static and route folders:
worker/fly.toml -> fly.indexer.toml
worker/Dockerfile -> worker.Dockerfile
fly.indexer.toml now points at worker.Dockerfile and pins one always-on
shared-cpu-1x / 256MB machine with no public ports (Jetstream worker
holds a long-lived outbound WebSocket; nothing inbound to accept).
The Dockerfile gains a slightly fuller header comment explaining the
expected build context, and drops the obsolete --unstable-fs flag (not
needed on Deno 2.x).
Made-with: Cursor