Fix residence detail caching to check both data sources

- APILayer.getResidence() now checks both residences and myResidences caches
- Home screen loads myResidences, but getResidence() only checked residences,
  causing unnecessary network calls on every residence detail visit
- Remove flawed iOS-side cache check in TaskViewModel that had race condition
  with Kotlin StateFlow - let Kotlin handle all caching logic

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

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

composeApp/src/commonMain/kotlin/com/example/casera/network/APILayer.kt

@@ -393,11 +393,21 @@ object APILayer {
     }
 
     suspend fun getResidence(id: Int, forceRefresh: Boolean = false): ApiResult<ResidenceResponse> {
-        // Check DataManager first - return cached if valid and not forcing refresh
-        if (!forceRefresh && DataManager.isCacheValid(DataManager.residencesCacheTime)) {
-            val cached = DataManager.residences.value.find { it.id == id }
-            if (cached != null) {
-                return ApiResult.Success(cached)
+        // Check DataManager caches first - return cached if valid and not forcing refresh
+        if (!forceRefresh) {
+            // Check residences list
+            if (DataManager.isCacheValid(DataManager.residencesCacheTime)) {
+                val cached = DataManager.residences.value.find { it.id == id }
+                if (cached != null) {
+                    return ApiResult.Success(cached)
+                }
+            }
+            // Also check myResidences (loaded from home screen)
+            if (DataManager.isCacheValid(DataManager.myResidencesCacheTime)) {
+                val cached = DataManager.myResidences.value?.residences?.find { it.id == id }
+                if (cached != null) {
+                    return ApiResult.Success(cached)
+                }
             }
         }