docs(auth,devices): Beam WO5 batch 3 — 15 endpoints backfilled, registry pinned

Beam backfilled auth core (login/register/refresh/logout/profile) and devices
core (list/update/delete/shelf CRUD/sidecar/register flow) with frontmatter,
provenance, and labeled examples. All claimed shapes verified against
handlers: AuthResponse {access_token, refresh_token omitempty, token_type,
expires_in, user}, update device {device_updated, device}, shelf wrappers,
DeviceAuthStatusResponse.

Claude registry verification: 15 entries pinned by type (LoginRequest,
RegisterRequest, AuthResponse, RefreshTokenRequest/Response, UserProfile,
DeviceListResponse, DeviceUpdateRequest, AddToShelfRequest, SidecarConfig,
DeviceRegistrationRequest/Response, DeviceAuthStatusRequest/Response).
Removed revoke_device.md — name-only duplicate of delete_device.md (same
DELETE /api/devices/:id route; was the last audit-orphan doc).

Gate catches this round (subtle Go serialization facts, now pinned in docs):
- uuid.UUID arrays never serialize as omitted: register/status response
  ALWAYS carries device_id (all-zeros while pending) despite omitempty
- update device request binds device_name, not name
- register response includes device_id alongside registration_id
- list devices response is a {devices, total} wrapper

docs/developer/api/devices/get_sidecar_config.md

@@ -1,3 +1,11 @@
+---
+method: GET
+path: /api/devices/:id/sidecar
+auth: jwt
+area: devices
+---
+<!-- source: internal/handlers/sidecar.go:67 SidecarHandler.GetSidecarConfig -->
+
 # Get Device Sidecar Config
 
 Returns the KOReader/Kobo sidecar configuration (`.bookhoard.json`) for a device: server endpoints, the user's books (keyed by SHA-256 with UUID fallback), and collections. Used by the Bookhoard KOReader plugin to self-configure after approval.
@@ -7,7 +15,7 @@ Returns the KOReader/Kobo sidecar configuration (`.bookhoard.json`) for a device
 
 ### Response (200 OK)
 
-```json
+```json example-response
 {
   "version": "1",
   "bookhoard": {