feat(api): enhance reading progress interfaces and add fetch endpoint

Update reading progress tracking on the frontend:
- Add epubcfi and percentage fields to ReadingProgress interface
- Add last_read_at timestamp for progress display
- Implement getReadingProgress() function to fetch current progress
- Export getReadingProgress for use in reader components

These changes align the frontend API with the new backend progress
schema and enable readers to retrieve saved position data.

web/src/api.ts

@@ -103,6 +103,9 @@ interface Chapter {
 interface ReadingProgress {
   current_page: number;
   total_pages: number;
+  epubcfi?: string;
+  percentage?: number;
+  last_read_at: string;
 }
 async function getReaderMetadata(mediaItemId: string): Promise<ReaderMetadata> {
   const response = await apiGet(`/media-items/${mediaItemId}`);
@@ -119,6 +122,18 @@ async function updateReadingProgress(
   await handleVoidResponse(response);
 }
 
+async function getReadingProgress(
+  mediaItemId: string,
+): Promise<ReadingProgress | null> {
+  const response = await apiGet(`/media-items/${mediaItemId}/progress`);
+
+  if (response.status === 404) {
+    return null;
+  }
+
+  return handleResponse<ReadingProgress>(response);
+}
+
 export {
   apiGet,
   apiPost,
@@ -129,8 +144,8 @@ export {
   handleVoidResponse,
   handleError,
   getReaderMetadata,
+  getReadingProgress, // ADD THIS
   updateReadingProgress,
-  ReaderMetadata,
   ReadingProgress,
   ChapterMetadata,
   Chapter,