refactor(bruno): migrate API tests to Bruno DSL format

- Convert all existing .bru files from JSON to Bruno DSL format
- Remove obsolete files (conflicts/api.bru, kobo/Kobo Initialization.bru)
- Update auth configuration to use 'inherit' instead of explicit bearer tokens
- Add comprehensive documentation to all test files
- Improve test scripts with proper assertions and error handling

bruno/collections/Get Collections.bru

@@ -6,9 +6,5 @@ meta {
 
 get {
   url: {{base_url}}/api/collections?include_auto=true&sort_by=name
-  auth: bearer
-}
-
-auth:bearer {
-  token: {{token}}
+  auth: inherit
 }