test(bruno): add manual API contract test for folder browsing

- Create bruno/library/browse-folders.yml
- Single manual test case for admin context
- Unit/integration tests cover all scenarios (no auth, user, admin)
- Bruno provides quick manual API contract verification

Fixes: Issue 2 (manual testing)

bruno/library/browse-folders.yml

@@ -0,0 +1,25 @@
+meta:
+  name: Browse library folders
+  type: http
+  seq: 1
+config:
+  test:
+    filter: "response.status == 200"
+    assertions:
+      - type: stddev
+        target: response_time
+        threshold: 1000
+      - type: jsonpath
+        expression: response.directories
+        condition: exists
+      - type: jsonpath
+        expression: response.current_path
+        condition: exists
+      - type: jsonpath
+        expression: response.parent_path
+        condition: exists
+req:
+  method: GET
+  url: "{{base_url}}/api/libraries/browse?path=/tmp"
+  headers:
+    Authorization: "Bearer {{ADMIN_TOKEN}}"