Replace the mandatory YouTube subtitle picker startup flow with automatic default-track loading. On YouTube playback start, attempt to load the default primary subtitle and best-effort secondary subtitle without prompting. Gate playback only on primary subtitle load/tokenization readiness. If primary subtitle probing/download/loading fails, resume playback and report the failure through the configured notification/output path. Keep the YouTube subtitle picker as a regular overlay modal opened by a new default keybinding during active YouTube playback.
Acceptance Criteria
#1 Opening a YouTube URL auto-selects and attempts to load the default primary subtitle without opening the picker modal.
#2 Opening a YouTube URL also attempts to load the default secondary subtitle when available, but playback never waits on secondary success.
#3 Playback remains gated only until the primary subtitle is loaded and tokenization is ready; primary failure resumes playback immediately.
#4 Primary auto-load failures report through the existing configured notification/output path and keep playback running.
#5 The YouTube subtitle picker can be opened manually during active YouTube playback via a new default keybinding.
#6 Regression tests cover startup auto-load success, primary failure fallback, and the manual picker keybinding flow.
Implementation Plan
Add failing tests for YouTube startup auto-load success, primary failure fallback, and manual picker keybinding flow.
Refactor the YouTube runtime to auto-select default tracks on startup, gate playback only on primary subtitle/tokenization readiness, and route failures through the configured notification/output path.
Add a new default keybinding and command path to open the YouTube picker manually during active YouTube playback.
Run targeted tests, then SubMiner verification lanes for launcher/runtime changes; update docs/changelog if required by the final behavior change.
Implementation Notes
Verification blocker outside this change: bun run test:fast still fails at scripts/update-aur-package.test.ts on macOS because scripts/update-aur-package.sh uses mapfile, which is unavailable in the system Bash 3.x environment used here.
Final Summary
Reworked app-owned YouTube playback to auto-load the default primary subtitle plus a best-effort secondary subtitle at startup instead of forcing the picker modal first. Playback now waits only on primary subtitle load/tokenization readiness, routes startup primary-failure messaging through the configured notification output path, and keeps the YouTube subtitle picker available on demand via a new default Ctrl+Shift+J keybinding during active YouTube playback. Updated the runtime/IPC/config plumbing, user-facing help/docs, and added regression coverage for startup auto-load, primary-failure fallback, and manual picker invocation.
