docs: add documentation for postgres logs (#45580)

Small docs update on new postgres logs behaviour

part of O11Y-1519

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **Documentation**
* Added a "Limits and Caveats" section clarifying Supabase
Platform-specific behavior for PostgreSQL RAISEd log messages: platform
log events are truncated at 100,000 characters (no truncation for
self-hosting), and certain internal PostgreSQL connection logs generated
by infrastructure services are omitted (these omissions do not apply to
self-hosted deployments).
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Co-authored-by: Chris Chinchilla <chris.ward@supabase.io>
Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

apps/docs/content/guides/telemetry/logs.mdx

@@ -213,6 +213,11 @@ show log_min_messages;
 
 Note that `LOG` is a higher level than `WARNING` and `ERROR`, so if your level is set to `LOG`, you will not see `WARNING` and `ERROR` messages.
 
+### Limits and caveats
+
+- Postgres log events on the Supabase Platform are limited to 100,000 characters. If a log event exceeds this limit, it will be truncated. This does not apply to self-hosting.
+- Internal connection logs to Postgres within the Supabase Platform by internal services are not logged. This does not apply to self-hosting.
+
 ## Logging realtime connections
 
 Realtime doesn't log new WebSocket connections or Channel joins by default. Enable connection logging per client by including an `info` `log_level` parameter when instantiating the Supabase client.