feat(backend): Create scheduled pool event indexing function

[rafamiziara]

Overview

Create Firebase scheduled function to index PoolCreated events every 5 minutes as backup mechanism.

Tasks

• Create functions/events/syncPoolEvents.ts scheduled function
• Configure Firebase Scheduler for 5-minute intervals
• For each supported chain: fetch PoolCreated events since last processed block
• Use shared eventIndexer service for each event
• Update event_sync_state collection with last processed block
• Add logging for indexed pools summary
• Implement retry logic for RPC failures

Acceptance Criteria

• Runs automatically every 5 minutes
• Successfully indexes missed pools from blockchain
• Updates sync state after each run
• Handles RPC errors gracefully with retries

Related Documentation

• See docs/POOL_CREATION_ARCHITECTURE.md Phase 5
• See docs/POOL_CREATION_TASKS.md Task 5

Labels: comp: backend, type: feature

Milestone: Sprint 3: Pool Creation

Part of Epic: #35