## Why
SQLite log persistence needs visibility into batch size, write latency,
failures, and entries dropped before they reach the writer. Exporter
diagnostics must not feed back into the SQLite log sink and keep metric
exports active indefinitely.
## What changed
- Record write count, duration, batch bytes, entry count, largest-entry size,
and queue drops with bounded outcome tags.
- Add explicit byte histogram boundaries for log batch metrics.
- Filter OTLP transport noise and the benign unsolicited HTTP/2 PING warning
from SQLite log persistence to prevent export cycles while retaining other
HTTP/2 warnings.
## Testing
- Cover metric values, tags, queue-drop reasons, and histogram boundaries.
- Verify successful and failed OTLP HTTP and gRPC exports become idle instead
of generating recurring SQLite log-write metrics.
GitOrigin-RevId: a63224ae15945fe84adc977a8b7d55bb47a4de53
## Summary
- add SQLite init, backfill-gate, and fallback telemetry without
introducing a cross-cutting state-db access wrapper
- install one process-scoped telemetry sink after OTEL startup and let
low-level state/rollout paths emit through it directly
- add process-start metrics for the process owners that initialize
SQLite
---------
Co-authored-by: Owen Lin <owen@openai.com>
Alexi Christakis