feat: completely remove Isolate Instrumental and 4-Stem Separation features

feat: completely remove Stem to MIDI feature from frontend and backend

feat: save extraction options to firebase and display active tools as badges in history

feat: phase 1-3 implementation (dashboard, history, audio health, sqlite, sse)

fix: mark missing tasks as Expired instead of deleting them from history

fix: Correct history UI for cancelled tasks to grey out status and button

fix: Update UI queue message, fix history page links, and extend cleanup to 48 hours

fix: Correct history page link for processing tasks to show progress

Optimize frontend UI for mobile responsiveness

Refine progress messages and UI binding for better user experience

Update history UI and integrate native DeepFilterNet for stronger noise reduction

fix: resolve all ESLint warnings and errors across frontend components

fix: resolve missing icon import causing build failure

feat: firebase history tracking and id search