Harden audio transcription fetch path with retries and timeout

docs/runbooks/VOICE_TRANSCRIPTION_DEBUG.md

@@ -39,9 +39,28 @@ curl -sS -i -X POST http://localhost:18801/v1/audio/transcriptions \
 - `Transcription endpoint error: FFmpeg conversion failed.`
   - Endpoint could not decode payload as audio. Often caused by model-provided fake or mismatched `data`/`mime_type`.
 
+- `fetch failed`
+  - Flynn could not connect to the transcription endpoint for that attempt (transport/connectivity timeout/reset).
+  - Confirm endpoint is reachable from Flynn host and check `whisper-server` logs around the same timestamp.
+  - If this is intermittent, Flynn now retries transient failures before returning an error.
+
 - `[No speech detected]`
   - Request succeeded and endpoint returned empty transcript text.
 
+## Correlate Events By Timestamp
+
+To inspect one Telegram session with wall-clock timestamps:
+
+```bash
+tail -n 2000 ~/.local/share/flynn/audit.log | jq -c '
+  select(
+    .event.session_id=="telegram:8367012007" and
+    (.event_type=="user.action" or .event_type=="backend.route" or .event_type=="tool.start" or .event_type=="tool.success" or .event_type=="tool.error")
+  )
+  | . + {ts_iso: ((.timestamp/1000)|strftime("%Y-%m-%d %H:%M:%S %Z"))}
+'
+```
+
 ## Rewrite Metric
 
 Flynn emits `tool.args_rewritten` whenever it replaces model-provided `audio.transcribe` args with trusted session audio bytes.