Add task completion history feature and UI improvements

- Add CompletionHistorySheet for viewing task completion history (Android & iOS)
- Update TaskCard and DynamicTaskCard with completion history access
- Add getTaskCompletions API endpoint to TaskApi and APILayer
- Update models (CustomTask, Document, TaskCompletion, User) for Go API alignment
- Improve TaskKanbanView with completion history integration
- Update iOS TaskViewModel with completion history loading

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

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

iosApp/iosApp/Task/CompleteTaskView.swift

@@ -311,7 +311,8 @@ struct CompleteTaskView: View {
             completedAt: nil,
             notes: notes.isEmpty ? nil : notes,
             actualCost: actualCost.isEmpty ? nil : KotlinDouble(double: Double(actualCost) ?? 0.0),
-            photoUrl: nil
+            rating: KotlinInt(int: Int32(rating)),
+            imageUrls: nil  // Images uploaded separately and URLs added by handler
         )
 
         // Use TaskCompletionViewModel to create completion