v0.3.0

Added

• Click-through mode: the panel no longer swallows clicks when you are working in another app.
  Three-state pointer policy (passthrough / armed / active): passes clicks through by
  default, fades to 12% while the pointer crosses it (still passing through), and only becomes
  interactive when explicitly summoned.
• Global hotkey ⌥⌘A to make the panel interactive / return it to click-through. Registered via
  Carbon RegisterEventHotKey, so it needs no Accessibility permission.
• Menu bar items: "Make panel interactive (⌥⌘A)" and "Auto yield (stay out of the way)". The menu
  bar icon switches between filled (interactive) and dimmed (click-through).
• .stationary collection behavior so the panel no longer slides with Space switches.

Fixed

• Settings were never persisted. UserDefaults(suiteName:) was passed the app's own bundle
  identifier, which macOS ignores ("Using your own bundle identifier as an NSUserDefaults suite
  name does not make sense and will not work"). This silently broke Launch at login too. Now
  uses UserDefaults.standard.
• Timers driving the pointer state machine never fired while the pointer hovered the panel:
  Timer.scheduledTimer runs in the default run loop mode, which is suspended in event-tracking
  mode. Timers are now added to .common.
• Panel could get stuck at ~0.3 alpha ("visible but unclickable") when two NSAnimationContext
  animations overlapped. Alpha is now assigned directly instead of animated.
• Occasional (~1 in 20) failure when summoning the panel with the hotkey: window properties were
  written before the state changed, letting a concurrent mouse event revert them. State is now
  switched first, and all property writes go through applyActive() / applyPassthrough().