Decompose indexer main.rs monolith into focused modules

[rustydb]

Priority: P1

Source

Senior Architect Code Review (2026-04-03)

Problem

apps/indexer/src/main.rs is an 849-line monolith containing:

• Configuration parsing (IndexerConfig)
• Database connection and schema management (Database)
• Sui RPC client and all API call methods (SuiRpcClient)
• Event processing pipeline (process_page, poll_until_caught_up)
• Cursor/state management (CursorState, merge_state)
• Health check HTTP server (start_health_check_server)
• All RPC response deserialization types (RpcEnvelope, RpcEventPage, etc.)
• Utility functions (parse_i64, parse_timestamp_ms, etc.)
• ~150 lines of inline tests

Meanwhile, handlers.rs and models.rs exist but the actual database interactions bypass the TurretEventStore trait entirely — main.rs has its own Database struct with direct tokio_postgres calls.

Recommendation

Extract into focused modules:

Module	Contents
config.rs	IndexerConfig, env parsing helpers
database.rs	Database struct, schema management, cursor CRUD, event insertion
rpc.rs	SuiRpcClient, all RPC types (RpcEnvelope, RpcEventPage, etc.)
pipeline.rs	process_page, poll_until_caught_up, PollSummary, PageOutcome
health.rs	start_health_check_server
main.rs	Entrypoint only — config, wiring, tokio::spawn

Also reconcile the TurretEventStore trait in handlers.rs with the actual database operations in main.rs.

Acceptance Criteria

• main.rs is under 100 lines (entrypoint and wiring only)
• Each module has a single responsibility
• The TurretEventStore trait is either used by the production path or removed
• All existing tests continue to pass
• No behavioral changes