- Fix float64 type assertions for JSON numbers in conflicts bulk operations
- Create fresh HTTP request body for duplicate book tests
- Add nil checks for type assertions in device cap tests
- Properly extract user_id from JWT for existing users
- Trim trailing whitespace from response bodies
- All 3 previously failing tests now passing
Test results: 19/22 passing (86.4%)
Fixes: TestCollectionsBulkOperations, TestConflictsBulkDismiss, TestUpdateUserMaxDevices
- Remove handler parameter from test function calls
- Update test signatures to use new return values from setupTestServer
- Fix compilation errors after test helper refactoring
- Maintain test functionality while simplifying setup