Docs: reminder — cursor ack state persistence tuning guide

[ng-galien]

Reminder

During the review of apache/pulsar#25548, @lhotari raised the need for a tuning guide alongside the new WARN log and metrics:

Adding documentation for the tuning together with the warning log in code will help. [...] Please go ahead with the warning log (and any documentation improvements).
— apache/pulsar#25540 (comment)

The related doc PR #1118 only covers the two new OpenTelemetry counters. The broader tuning guide hasn't been written.

Opening this as a reminder so it doesn't get lost. Happy to pass it on to anyone with the right context on the project to pick it up.

References

• Original issue: Add WARN log when cursor ack holes exceed managedLedgerMaxUnackedRangesToPersist pulsar#25540
• Code PR: [improve][ml] Warn and emit metric when cursor ack state exceeds persist limits pulsar#25548
• Metric doc PR: Docs: document cursor persist truncation OpenTelemetry metrics #1118
• lhotari's tuning input: Add WARN log when cursor ack holes exceed managedLedgerMaxUnackedRangesToPersist pulsar#25540 (comment)