Update client models to handle numeric decimals from optimized API

Model type updates:
- Change decimal cost fields from String to Double for better type safety
- actualCost: String? → Double? (TaskCompletion, TaskCompletionCreateRequest)
- estimatedCost: String? → Double? (CustomTask, TaskCreateRequest, TaskDetail)
- purchasePrice: String? → Double? (Residence, ResidenceCreateRequest)

TaskDetail model fixes:
- Add missing residenceName, createdBy, createdByUsername fields
- Add missing intervalDays field to match backend response
- Remove actualCost and notes fields (not in backend TaskDetailSerializer)
- Ensure 100% compatibility with Django API TaskDetailSerializer

UI input/output conversions:
- EditTaskScreen: Convert Double to String for display, String to Double for API
- AddTaskDialog: Convert String input to Double for API requests
- CompleteTaskDialog: Convert String input to Double for API requests
- App.kt: Handle type conversions in navigation route parameters

Display improvements:
- TaskCard: Update preview data to use numeric literals (150.00 vs "150.00")
- Cost display already handles Double correctly with string interpolation

Benefits:
- Type-safe numeric handling throughout the app
- Smaller JSON payloads (numbers vs quoted strings)
- Better performance with direct numeric deserialization
- Aligns with REST API best practices
- 100% backend compatibility verified

Testing:
- All models now match backend serializer field types exactly
- Build successful with no errors
- Ready for integration with optimized Django API

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

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

composeApp/src/commonMain/kotlin/com/example/mycrib/models/CustomTask.kt

@@ -17,8 +17,8 @@ data class CustomTask (
     val status: TaskStatus? = null,
     @SerialName("due_date") val dueDate: String?,
     @SerialName("next_scheduled_date") val nextScheduledDate: String? = null,
-    @SerialName("estimated_cost") val estimatedCost: String? = null,
-    @SerialName("actual_cost") val actualCost: String? = null,
+    @SerialName("estimated_cost") val estimatedCost: Double? = null,
+    @SerialName("actual_cost") val actualCost: Double? = null,
     @SerialName("completion_count") val completionCount: Int? = null,
     val notes: String? = null,
     val archived: Boolean = false,
@@ -34,7 +34,7 @@ data class CustomTask (
 data class LastCompletion(
     @SerialName("completion_date") val completionDate: String,
     @SerialName("completed_by") val completedBy: String?,
-    @SerialName("actual_cost") val actualCost: String?,
+    @SerialName("actual_cost") val actualCost: Double?,
     val rating: Int?
 )
 
@@ -49,7 +49,7 @@ data class TaskCreateRequest(
     val priority: Int,
     val status: Int? = null,
     @SerialName("due_date") val dueDate: String,
-    @SerialName("estimated_cost") val estimatedCost: String? = null,
+    @SerialName("estimated_cost") val estimatedCost: Double? = null,
     val archived: Boolean = false
 )
 
@@ -57,8 +57,9 @@ data class TaskCreateRequest(
 data class TaskDetail(
     val id: Int,
     val residence: Int,
-    //@SerialName("created_by") val createdBy: Int,
-    //@SerialName("created_by_username") val createdByUsername: String,
+    @SerialName("residence_name") val residenceName: String? = null,
+    @SerialName("created_by") val createdBy: Int? = null,
+    @SerialName("created_by_username") val createdByUsername: String? = null,
     val title: String,
     val description: String?,
     val category: TaskCategory,
@@ -66,9 +67,8 @@ data class TaskDetail(
     val frequency: TaskFrequency,
     val status: TaskStatus?,
     @SerialName("due_date") val dueDate: String?,
-    @SerialName("estimated_cost") val estimatedCost: String? = null,
-    @SerialName("actual_cost") val actualCost: String? = null,
-    val notes: String? = null,
+    @SerialName("interval_days") val intervalDays: Int? = null,
+    @SerialName("estimated_cost") val estimatedCost: Double? = null,
     val archived: Boolean = false,
     @SerialName("created_at") val createdAt: String,
     @SerialName("updated_at") val updatedAt: String,