* use server response for local state updates
* fix formatting
* refactor: comprehensive server-response-first pattern implementation
## Major Changes
### LayerProps ID Required
- Made `LayerProps.id` required (was optional)
- All layers now guaranteed to have server-provided UUID
- Enables reliable layer ID mapping from server responses
### useSelectPosition Hook Refactored
- Added reusable `handleApiOperation` helper function
- Refactored `itemUpdatePosition`, `itemUpdateParent`, `linkItem`
- All functions now use server response + layer ID mapping
- Consistent error handling and toast management
### itemFunctions.ts Complete Refactor
- **submitNewItem**: Server response with layer mapping
- **linkItem**: Server response preserves layer object
- **unlinkItem**: Same pattern as linkItem
- **handleDelete**: Simplified error handling
- **onUpdateItem**: Complex function refactored for both update/create branches
### Benefits
- ✅ Eliminates race conditions from manual state construction
- ✅ Server response as single source of truth for all updates
- ✅ Consistent error handling across all API operations
- ✅ Items no longer disappear from map after updates
- ✅ Type-safe layer ID mapping
### Testing
- Updated ItemFunctions.spec.tsx with new toast patterns
- Added required layer IDs to test objects
- All 19 tests passing (3 skipped)
- ESLint clean
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
* fix linting
* fix: resolve TypeScript undefined data errors
- Add non-null assertions for result.data in conditional blocks
- TypeScript now properly recognizes data is defined after success check
- All linting and TypeScript errors resolved
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
* fixed examples
* remove unneccessary uuid generation
---------
Co-authored-by: Claude <noreply@anthropic.com>
