test(communities): Add comprehensive integration and E2E tests
Test coverage:
- Repository layer: CRUD, subscriptions, search, pagination
- Consumer layer: Event handling, idempotency, filtering
- E2E: Write-forward → PDS → Firehose → Consumer → AppView → XRPC
E2E test validates:
- Full atProto write-forward architecture
- Real PDS integration (not mocked)
- Jetstream consumer indexing
- All XRPC HTTP endpoints
- Data consistency across layers
Test cleanup:
- Removed duplicate writeforward_test.go
- Removed incomplete xrpc_e2e_test.go
- Removed manual real_pds_test.go
- Kept only essential, non-overlapping tests
All tests passing ✅