✨ feat: add @manacore/shared-api-client package

Create unified API client for all web apps with:
- createApiClient factory function
- ApiResult<T> Go-style error handling
- HTTP methods: get, post, put, patch, delete, upload
- Auto token handling via getAuthToken callback
- Timeout support with AbortController
- Retry logic with exponential backoff
- Runtime URL injection for Docker
- FormData support for file uploads

Migrate clock app as proof of concept:
- Replace local fetchApi with shared createApiClient
- Update stores to use ApiError.message

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

packages/shared-api-client/src/index.ts

@@ -1,7 +1,51 @@
 /**
- * Shared API Client for ManaCore Apps
- * Provides a unified way to make API calls with authentication.
+ * @manacore/shared-api-client
+ *
+ * Unified API client for all ManaCore web applications.
+ * Provides consistent error handling, token management, and retry logic.
+ *
+ * @example
+ * ```typescript
+ * import { createApiClient } from '@manacore/shared-api-client';
+ * import { authStore } from '$lib/stores/auth.svelte';
+ *
+ * // Create client instance
+ * export const api = createApiClient({
+ *   baseUrl: 'http://localhost:3014',
+ *   apiPrefix: '/api/v1',
+ *   getAuthToken: () => authStore.getValidToken(),
+ *   timeout: 30000,
+ *   retries: 2,
+ * });
+ *
+ * // Make requests
+ * const { data, error } = await api.get<User[]>('/users');
+ *
+ * if (error) {
+ *   if (error.code === 'UNAUTHORIZED') {
+ *     // Handle auth error
+ *   }
+ *   console.error('API Error:', error.message);
+ *   return;
+ * }
+ *
+ * // data is typed as User[]
+ * console.log('Users:', data);
+ * ```
  */
 
-export { createApiClient, type ApiClientConfig, type ApiClient } from './client';
-export { type ApiResponse, type FetchOptions, type HttpMethod } from './types';
+// Client factory
+export { createApiClient } from './client';
+
+// Types
+export type {
+	ApiClient,
+	ApiClientConfig,
+	ApiError,
+	ApiErrorCode,
+	ApiResult,
+	RequestOptions,
+} from './types';
+
+// Utilities
+export { buildQueryString, getBaseUrl } from './utils';