Add contractor management and integrate with task completions

Features:
- Add full contractor CRUD functionality (Android & iOS)
- Add contractor selection to task completion dialog
- Display contractor info in completion cards
- Add ContractorSpecialty model and API integration
- Add contractors tab to bottom navigation
- Replace hardcoded specialty lists with API data
- Update lookup endpoints to return arrays instead of paginated responses

Changes:
- Add Contractor models (ContractorSummary, ContractorDetail, ContractorCreate/UpdateRequest)
- Add ContractorApi with endpoints for list, detail, create, update, delete, toggle favorite
- Add ContractorViewModel for state management
- Add ContractorsScreen and ContractorDetailScreen for Android
- Add AddContractorDialog with form validation
- Add Contractor views for iOS (list, detail, form)
- Update CompleteTaskDialog to include contractor selection
- Update CompletionCardView to show contractor name and phone
- Add contractor field to TaskCompletion model
- Update LookupsApi to return List<T> instead of paginated responses
- Update LookupsRepository and LookupsViewModel to handle array responses
- Update LookupsManager (iOS) to handle array responses for contractor specialties

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

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

iosApp/iosApp/MainTabView.swift

@@ -22,13 +22,21 @@ struct MainTabView: View {
             }
             .tag(1)
 
+            NavigationView {
+                ContractorsListView()
+            }
+            .tabItem {
+                Label("Contractors", systemImage: "wrench.and.screwdriver.fill")
+            }
+            .tag(2)
+
             NavigationView {
                 ProfileTabView()
             }
             .tabItem {
                 Label("Profile", systemImage: "person.fill")
             }
-            .tag(2)
+            .tag(3)
         }
     }
 }