Phase 3 Week 7: Add KOReader routes, tests, and documentation

- Add KOReader sync endpoints to main application router
- Create Bruno API collection for testing KOReader endpoints
- Add integration tests for KOReader functionality
- Include comprehensive README with setup instructions
- Test coverage for progress, metadata, library, and bookmarks sync
- Part of Phase 3 KOReader Integration implementation

bruno/koreader/Sync Bookmarks.bru

@@ -0,0 +1,60 @@
+meta {
+  name: KOReader Sync Bookmarks
+  type: http
+  seq: 4
+}
+
+post {
+  url: {{baseUrl}}/api/sync/koreader/bookmarks
+  body: json({
+    "book_uuid": "{{book_uuid}}",
+    "bookmarks": [
+      {
+        "chapter": 3,
+        "datetime": "2026-01-30T19:55:00Z",
+        "notes": "Bookmarked text",
+        "pos0": "epubcfi(/6/4/2:15)",
+        "pos1": "epubcfi(/6/4/2:20)",
+        "page": 45,
+        "text": "This is important",
+        "type": "highlight",
+        "percentage": 0.45
+      }
+    ],
+    "notes": [
+      {
+        "chapter": 3,
+        "datetime": "2026-01-30T19:55:00Z",
+        "notes": "My note here",
+        "pos0": "epubcfi(/6/4/2:15)",
+        "page": 45,
+        "text": "Note content",
+        "type": "note"
+      }
+    ],
+    "highlights": [
+      {
+        "chapter": 3,
+        "datetime": "2026-01-30T19:55:00Z",
+        "notes": "highlighted text",
+        "pos0": "epubcfi(/6/4/2:15)",
+        "pos1": "epubcfi(/6/4/2:20)",
+        "page": 45,
+        "text": "highlighted text excerpt",
+        "type": "highlight",
+        "color": "#ffff00",
+        "percentage": 0.45
+      }
+    ]
+  })
+  headers: {
+    Authorization: Bearer {{device_token}},
+    Content-Type: application/json
+  }
+}
+
+assert {
+  res.status == 200
+  res.body.sync_status == "completed"
+  res.body.total_synced >= 0
+}