rename: Outlook Relook → Outcut, add keyboard presets, remove design UI from popup

- Rename extension to "Outcut" throughout all source files and console logs
- Add KEY_PRESETS object (gmail/outlook) and matchesAction() helper to keyboard.js
- Rewrite handleKeydown to use preset-based dispatch instead of hardcoded switch
- Update updateSettings to re-init when keyboardPreset changes
- Add keyboardPreset: 'gmail' default to settings-defaults.js
- Replace popup Design Tweaks UI with preset dropdown + dynamic help text
- Keep all design tweak content script logic intact (activatable via storage)
- Update manifest: version 1.0.0, remove activeTab, add homepage_url

content/settings-defaults.js

@@ -6,6 +6,7 @@ window.OutlookRelook = window.OutlookRelook || {};
 window.OutlookRelook.DEFAULTS = {
   // Keyboard Navigation (primary feature, always visible)
   keyboardMultiSelect: true,
+  keyboardPreset: 'gmail',
 
   // Design Tweaks (experimental, hidden by default)
   enableDesignTweaks: false,