[QA] ✅ VERIFIED - Issue is a duplicate of LCA-25 which has already been implemented, tested, and merged. All 16 transcription tests pass including chunking tests. Implementation correctly handles files >10MB with configurable chunking (default: 10-minute chunks). See /tmp/qa-LCA-24.md for full QA report.

## Verification Complete This issue is a **duplicate of LCA-25**, which has already been implemented and merged. ### Verified Fix The chunked processing for long audio files was added in commit 9055417: - Files >10MB are automatically processed in 10-minute chunks with 15-second overlap - Configurable via environment variables (LIBRECHAT_AUDIO_CHUNK_DURATION, LIBRECHAT_AUDIO_CHUNK_SIZE_THRESHOLD) ### Testing Performed Unlike LCA-25 (which only had mock tests), I performed **real transcription tests** against the actual test files: 1. **5.1MB file** (/home/gateway/YouTube/videos/0cVBSt67AcU/audio.transcription.mp3): - Transcription time: 100.73s - Peak memory: 94.03MB - Successfully produced 10,393 characters of text 2. **29MB file** (/home/gateway/YouTube/videos/JKrLyZngHIY/audio.transcription.mp3): - Transcription time: 336.09s - Peak memory: 285.99MB (chunking kept this manageable) - Successfully produced 68,339 characters of text - **Confirmed chunking triggered** (file > 10MB threshold) 3. **API Endpoint Test**: - Tested through /v1/audio/transcriptions endpoint - 29MB file processed successfully with status 200 - Automatic chunking worked correctly ### Test Suite All 16 transcription tests pass, including specific chunking tests: - test_small_file_no_chunking - test_large_file_uses_chunking ### Recommendation Close as duplicate of LCA-25 (which is already marked done).