⚡ Bolt: Use connection pooling for health endpoint

[kourdroid]

💡 What:
Replaced the direct asyncpg.connect(...) call in the /health endpoint with get_connection_pool(settings.database_url).

🎯 Why:
The /health endpoint is typically hit very frequently (e.g., by load balancers or orchestrators). Creating a brand new database connection for every health check introduces significant, unnecessary TCP and TLS handshake overhead, and can quickly exhaust the database's max connection limit. Using a shared connection pool drastically reduces latency on these repetitive calls.

📊 Impact:
Eliminates TCP/TLS and PostgreSQL startup handshake overhead per health check request, transforming O(N) connection overhead (where N is the number of health checks over time) into roughly O(1) connection reuse.

🔬 Measurement:
Monitor the latency of the /health endpoint and the number of active database connections before and after deployment. Both should see a measurable decrease, especially under load.

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PR created automatically by Jules for task 1232076665411462146 started by @kourdroid

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