# Telemetry Debug Mode

Phase 72.5.1.10 adds `@v2/telemetry-debug-mode`, the development-only verbose
logging layer for telemetry event inspection.

## Development Logging

`debugTelemetryBatch` logs every event in a telemetry batch when `enabled: true`
and the build configuration is `development`, `test`, `qa`, or `staging`. Each
`TelemetryDebugRecord` contains the batch ID, producer, topic, event ID, session
ID, sequence, critical flag, payload schema version, sanitized payload, and a
deterministic single-line message produced by `formatTelemetryDebugRecord`.

Use `MemoryTelemetryDebugSink` for tests and local tooling. Runtime adapters can
forward each record line to engine logging, but the package itself stays pure
and does not write to process-global console output.

## Release Safety

`resolveTelemetryDebugModeConfig` normalizes build names and always disables
debug logging for `release`, `production`, and `shipping` builds. A requested
release build returns `release-build-disabled`, logs zero events, and writes
nothing to the configured sink. Debug mode is opt-in; unrequested development
builds return `debug-mode-disabled`.

## Payload Hygiene

`sanitizeTelemetryDebugPayload` redacts forbidden ingestion fields, token
fields, password fields, secret fields, raw log lines, email, IP address, and
platform user identifiers before log formatting. Long string values are
truncated to `maxPayloadValueCharacters`, and `includePayload: false` emits
metadata-only records for safer local captures.

Targeted verification:

```bash
pnpm --filter @v2/telemetry-debug-mode run typecheck
pnpm --filter @v2/telemetry-debug-mode run test
python V2/ue/Tools/check-v2-telemetry-debug-mode.py
```