SuperSearch v0.1.12

Fixes two settings-window bugs found during a UI pass, and adds a real
light/dark base theme alongside the existing accent picker.

Fixed

• Behavior toggle switch overflowed its track. The switch thumb had no
  base horizontal anchor (left), so the browser fell back to a
  static-position heuristic that rendered it flush against — and partly
  outside — the track's right edge in the checked state. Anchored with
  left-0 so translate-x-* offsets are relative to a known origin.
• Global hotkey capture looked stuck on "Listening…". The bound toggle
  shortcut stays registered as an OS-level global hotkey the entire time the
  settings window is open, so pressing that combo (or anything already
  intercepted) while recording a new one never reached the capture
  keydown listener — the OS grabbed it first. The settings window now
  suspends the active global hotkey for the duration of a capture session
  (suspend_toggle_shortcut) and re-arms it on cancel, failure, or unmount
  (resume_toggle_shortcut); a successful capture re-registers the new
  combo instead, via the existing update_settings → rebind_toggle path.

Added

• Base theme selector. Appearance now has a Dark/Light theme picker
  alongside Accent Color, independent of it. Every settings-window surface
  reads its ink/canvas colors from CSS variables (--ink-rgb,
  --canvas-rgb) flipped by theme.ts:applyTheme(), so switching themes
  repaints the whole window instantly — no reload.