[api] Sync indexer event tables into Pool, Swap, and Position models

[Mimah97]

Problem

IndexerWorker writes only to event tables (pool_created, swap_processed, etc.). Relational pool, swap, and position tables stay empty, breaking /pools, /swaps, portfolio views, and StatsWorker.

Acceptance criteria

• On PoolCreated → upsert Pool + Token records
• On SwapProcessed → insert Swap, update pool state
• On PositionMinted / PositionBurned → upsert or close Position
• Idempotent on eventId
• Integration test with test DB

Files

• apps/api/src/indexer/indexer.worker.ts