Add comprehensive error message parsing to prevent raw JSON display

- Created ErrorMessageParser utility for both iOS (Swift) and Android (Kotlin)
- Parser detects JSON-formatted error messages and extracts user-friendly text
- Identifies when data objects (not errors) are returned and provides generic messages
- Updated all API error handling to pass raw error bodies instead of concatenating
- Applied ErrorMessageParser across all ViewModels and screens on both platforms
- Fixed ContractorApi and DocumentApi to not concatenate error bodies with messages
- Updated ApiResultHandler to automatically parse all error messages
- Error messages now show "Request failed. Please check your input and try again." instead of raw JSON

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

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

iosApp/iosApp/Residence/ResidenceDetailView.swift

@@ -148,6 +148,10 @@ struct ResidenceDetailView: View {
         .onAppear {
             loadResidenceData()
         }
+        .handleErrors(
+            error: viewModel.errorMessage,
+            onRetry: { loadResidenceData() }
+        )
     }
 }
 
@@ -158,10 +162,6 @@ private extension ResidenceDetailView {
     var mainContent: some View {
         if !hasAppeared || viewModel.isLoading {
             loadingView
-        } else if let error = viewModel.errorMessage {
-            ErrorView(message: error) {
-                loadResidenceData()
-            }
         } else if let residence = viewModel.selectedResidence {
             contentView(for: residence)
         }
@@ -328,7 +328,7 @@ private extension ResidenceDetailView {
                     if result is ApiResultSuccess<KotlinUnit> {
                         dismiss()
                     } else if let errorResult = result as? ApiResultError {
-                        self.viewModel.errorMessage = errorResult.message
+                        self.viewModel.errorMessage = ErrorMessageParser.parse(errorResult.message)
                     } else {
                         self.viewModel.errorMessage = "Failed to delete residence"
                     }