Address six gaps found during review:
- Fix subreddit name extraction bug (gear icon text in textContent)
- Prevent gear icon layout shift via absolute positioning
- Handle native color picker dialog in click-outside detection
- Make per-subreddit overrides mode-aware (light/dark)
- Replace badge hover opacity with filter: brightness
- Split popover logic into separate file
Co-authored-by: Cursor <cursoragent@cursor.com>
