Review observability coverage for this feature group.

For every feature listed, verify the implementation has:
- Structured logging at appropriate levels (debug, info, warn, error).
- Distributed tracing spans with meaningful names and attributes.
- Prometheus metrics where applicable (counters, histograms, gauges).
- Error logging with sufficient context for debugging.

If observability is missing or insufficient, add it.
Score 0–100 based on observability completeness AFTER your fixes.
