v13.5.5

## Telemetry Reliability Signals (Plan 14)

claude-mem instrumented success well — failure was invisible. This release adds the five highest-value missing reliability signals (#2874). Everything is closed-enum/count-only, whitelisted in the scrubber, and disclosed in both the [public docs](https://docs.claude-mem.ai/telemetry) and `claude-mem telemetry`.

### Search retrieval quality (`search_performed`)
- `result_count`, `search_strategy` (`chroma|fts|filter_only`), `chroma_available`, `fallback_reason` (`none|chroma_connection|chroma_error|chroma_not_initialized`)
- Zero-result rate is now computable, and Chroma's silent degradation to FTS is visible.

### Compression trust (`session_compressed`)
- `fabrication_detected` / `fabricated_count` — commit-hash fabrication by the observer model, on every emit path
- Respawn-gated invalid-output events: `invalid_output_class` (`xml|idle|prose|poisoned`), `consecutive_invalid_outputs`, `respawn_triggered`
- `outcome: aborted` with `abort_reason` (`idle|shutdown|overflow|restart_guard|quota|poisoned|none`), emitted where all abort flows converge

### Worker lifecycle
- New `worker_stopped` event: `uptime_seconds`, `shutdown_reason` (`stop|restart|signal`)
- Crash detection via clean-shutdown sentinel: `worker_started` now reports `previous_shutdown` (`crash|clean|unknown`) and `previous_uptime_seconds`
- Memory health: integer `process_rss_mb` / `heap_used_mb` on lifecycle events and the heartbeat

### Hook failures
- New `hook_failed` event over the direct CLI transport (the worker being unreachable IS the failure being reported), threshold-gated on the fail-loud counter and awaited before process exit so events survive short-lived hook processes

### Fixes
- **CI**: the PostHog `disableGeoip` regression test was order-dependent and failed full-suite runs (CI on main had been red since v13.5.4). `posthog-node` is now mocked globally via a bun test preload — which also guarantees test runs can never construct a real PostHog client and flush fabricated events into production analytics.
- Windows-managed shutdown IPC now forwards the restart reason for `shutdown_reason` fidelity.