Add Indian tala and time signature detection alongside Western BPM

Add admin dashboard with download history and persistent storage

Fix page scroll overflow, add credits, and add HF Space deployment

feat(stems): add multi-stem downloads with Playwright e2e coverage

feat(trim): add upload trim range with preview and backend segment processing

chore: pre-deployment cleanup and fixes

fix: replace assert with RuntimeError guard, truncate stderr before decode

feat: demucs processing worker with asyncio queue and MPS acceleration

fix: init asyncio queue inside startup event, add QueueFull guard

feat: job store and GET /status/{job_id} endpoint