Lukas
5166789b68
Introduce discriminated FetchError union type to replace weak string error handling in API calls and hooks. Enables actionable error diagnostics. Changes: - Create types/api.ts with FetchError discriminated union (api_error, network_error, abort_error) - Export type guards: isAuthError, isAbortError, isNetworkError, isApiError - Update useListData and usePolledData to expose typed FetchError instead of string - Add getErrorMessage() helper to extract displayable messages from FetchError - Add createStringErrorAdapter() for backward compatibility with string error state - Update handleFetchError() to work with both FetchError and string setters - Update all consumer hooks to expose typed errors - Update components to use getErrorMessage() when displaying errors - Update tests to mock FetchError instead of strings - Add comprehensive typed error model documentation to Web-Development.md This enables better error handling patterns: - Check error.type to distinguish between API, network, and abort errors - Extract status codes for specific handling (401/403 auth, 50x server errors) - Maintain backward compatibility with existing string-based error states All TypeScript compilation passes with no errors. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>