fix: correct API endpoint path from /api/library/scan-settings to /api/libraries/scan-settings

- Update endpoint path in Get Scan Settings Bruno collection file
- Update endpoint path in Update Scan Settings Bruno collection file
- Update endpoint path in API reference documentation

This corrects a typo in the API path where 'library' was singular instead of plural.

docs/developer/api-reference.md

@@ -199,7 +199,7 @@ Content-Type: application/json
 ### Update Scan Settings
 
 ```http
-PUT /api/library/scan-settings
+PUT /api/libraries/scan-settings
 Authorization: Bearer <token>
 Content-Type: application/json