Remove manual token login/logout — single auth path via desktop app

Use stored HF token for dataset operations (no manual token required)

Refactor marionette into modules, fix audio sync, improve tests

Simplify replay compensation: always-on lead model, default lead tuned, and GUI tuning UX

Sync fix

fix(playback): sync audio and motion start, enable lead compensation

Fix HF login lost on restart and improve token hint text

Add HF manual token login/logout in settings drawer

Add configurable welcome messages (0/1/2) at startup

Fix tester-reported bugs: stop responsiveness, dropdown race, debounce

Add AGC, API contract, and E2E tests for refactoring protection

Expand test suite to ~170 tests across 3 tiers

Fix recording freeze: handle queued mode in stop endpoint

Fix HF test: allow real username when huggingface_hub is installed

Separate local and downloaded datasets: block recording into downloads

Add HF auto-login detection: auto-fill username from CLI session

Add 'starting_up' mode for non-blocking startup animation

Remove denoise feature from UI and backend

Fix P0-1: Replace fragile progress bar timing with server-driven phases

Add test infrastructure: 50 unit tests + 13 Playwright E2E tests