test: add Bruno API test collections for device authentication

- Device token regeneration tests (success, forbidden, not found, unauthorized)
- OPDS authentication tests (Bearer token, query token)
- Kobo sync tests with token authentication
- Test various authentication methods and error cases

bruno/devices/regenerate-token-unauthorized.bru

@@ -0,0 +1,24 @@
+meta {
+  name: Regenerate Device Token - Unauthorized
+  type: http
+  seq: 2
+}
+
+put {
+  url: {{base_url}}/api/devices/{{device_id}}/regenerate-token
+  body: none
+  auth: none
+}
+
+docs {
+  ## Regenerate Device Token - Unauthorized
+
+  Tests that token regeneration requires authentication.
+
+  **Expected Behavior:** Returns 401 Unauthorized when no Bearer token is provided
+
+  **Status Codes:**
+  - 401: Unauthorized (missing or invalid token)
+
+  **Use Case:** Verify authentication is required for token regeneration
+}