[api] Trigger WebhooksService.dispatch from indexer handlers

[Mimah97]

Problem

Webhook CRUD and delivery worker exist in apps/api/src/webhooks/, but nothing in the indexer pipeline calls WebhooksService.dispatch().

Acceptance criteria

• Dispatch SWAP, LARGE_SWAP, POSITION_MINTED, POSITION_BURNED events
• Respect webhook eventTypes filtering
• Test that matching webhooks enqueue delivery jobs

Files

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