Add haptic feedback, rich task completion, and Google Sign-In preparation

- Add platform haptic feedback abstraction (HapticFeedback.kt) with
  implementations for Android, iOS, JVM, JS, and WASM
- Enhance CompleteTaskDialog with interactive 5-star rating, image
  thumbnails, and haptic feedback
- Add ImageBitmap platform abstraction for displaying selected images
- Localize TaskTemplatesBrowserSheet with string resources
- Add Android widgets infrastructure (small, medium, large sizes)
- Add Google Sign-In button components and auth flow preparation
- Update strings.xml with new localization keys for completions,
  templates, and document features
- Integrate haptic feedback into ThemePickerDialog

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

composeApp/src/androidMain/res/values/strings.xml

@@ -1,4 +1,14 @@
 <resources>
     <string name="app_name">Casera</string>
     <string name="default_notification_channel_id">casera_notifications</string>
+
+    <!-- Widget Strings -->
+    <string name="widget_small_name">Casera Summary</string>
+    <string name="widget_small_description">Quick task count summary showing overdue, due soon, and active tasks</string>
+
+    <string name="widget_medium_name">Casera Tasks</string>
+    <string name="widget_medium_description">List of upcoming tasks with quick access to task details</string>
+
+    <string name="widget_large_name">Casera Dashboard</string>
+    <string name="widget_large_description">Full task dashboard with stats and interactive actions (Pro feature)</string>
 </resources>