docs(kobo,koreader,collections): Beam WO5 batch 6 — 12 endpoints

Kobo emulation + KOReader calibre-compatible surface backfilled with
device-token auth; collections reorder + update_rule created.

Claude registry: 12 entries. kobo/koreader emulation endpoints all bind
arbitrary protocol POST bodies (markup/bookmark/gettests/sync-from-server,
koreader progress/bookmarks) — registered as AnyJSONObject, not bodyless as
first drafted. Initialization returns the library sync payload, not the init
response.

Contract correction in update_rule.md: the route is SetRuleEnabled ({enabled}
required -> {collection_id, is_smart}); Beam's draft invented rule-field
updates. Reordered response/status: {item_ids} -> {status: reordered}.

make test 9/9.

docs/developer/api/kobo/sync_from_server.md

@@ -1,3 +1,11 @@
+---
+method: POST
+path: /api/sync/kobo/:token/sync-from-server
+auth: device-token
+area: kobo
+---
+<!-- source: internal/handlers/kobo.go:751 KoboHandler.SyncFromServer -->
+
 # Sync From Server
 
 > **Status: Coming Soon** — Native Kobo sync is not yet supported on real devices; this endpoint is under active development and may change.
@@ -20,7 +28,7 @@ This endpoint requires device authentication (not user JWT). Kobo devices authen
 
 ### Example Request
 
-```json
+```json example-request
 {
   "book_ids": ["content-id-1", "content-id-2"],
   "full_sync": false
@@ -29,24 +37,11 @@ This endpoint requires device authentication (not user JWT). Kobo devices authen
 
 ## Response (200 OK)
 
-```json
+```json example-response
 {
-  "books": [
-    {
-      "ContentID": "content-id-1",
-      "Title": "Book Title",
-      "Author": "Author Name",
-      "ISBN": "978-0123456789",
-      "PublicationDate": "2026-02-08",
-      "FileSize": 1234567,
-      "CoverImageId": "cover-id-1",
-      "Metadata": {
-        "language": "en",
-        "publisher": "Publisher Name"
-      }
-    }
-  ],
-  "total": 2
+  "BookmarksSent": null,
+  "BooksSynced": null,
+  "HighlightsSent": null
 }
 ```