- Add a check requiring `cacheWrite > 0` to identify meaningful cache invalidation.
- Prevent false positives for providers with implicit caching that intermittently report zero reads without a fresh cache write.
- Add regression test case to verify implicit providers are not flagged as invalidations.
- Implemented `detectCacheInvalidation` to identify when model requests lose their prompt cache.
- Added `CacheInvalidationMarkerComponent` to display a slim notice above affected assistant turns.
- Updated `ChatTranscriptBuilder` and `EventController` to track session usage and inject markers dynamically.
- Included comprehensive test coverage for invalidation detection logic and UI rendering.
can1357