feat: Add comprehensive todo management system with Gemini-powered brain dump analysis

- Add TodoEntity, TodoDao, TodoRepository, and TodoRepositoryImpl for local todo storage with sync support
- Implement TodoViewModel with CRUD operations, group management, and subtask handling
- Create TodoScreen with Kanban-style board view, group-based organization, and drag-to-reorder support
- Add BrainDumpSheet for AI-powered task extraction from natural language input using Gemini API
- Implement TodoNot

app/proguard-rules.pro

@@ -5,13 +5,11 @@
 # For more details, see
 #   http://developer.android.com/guide/developing/tools/proguard.html
 
-# Keep classes used for serialization
--keepattributes *Annotation*,EnclosingMethod,InnerClasses
--keepattributes Signature
--keepattributes SourceFile,LineNumberTable
+# Keep classes used for serialization + reflection metadata required by Retrofit
+-keepattributes Signature,Exceptions,*Annotation*,InnerClasses,EnclosingMethod,SourceFile,LineNumberTable,RuntimeVisibleAnnotations,RuntimeVisibleParameterAnnotations
 
 # Retrofit
--keepattributes RuntimeVisibleAnnotations, RuntimeVisibleParameterAnnotations
+-keep interface com.shaarit.data.api.** { *; }
 -keepclassmembers,allowshrinking,allowobfuscation interface * {
     @retrofit2.http.* <methods>;
 }
@@ -61,7 +59,6 @@
 
 # Keep Kotlin Metadata
 -keep class kotlin.Metadata { *; }
--keepattributes RuntimeVisibleAnnotations
 
 # Hilt / Dagger
 -keepclasseswithmembers class * {