refactor(bruno): reorganize file structure from bruno-yaml to flat bruno directory

- Move all files from bruno-yaml/* to bruno/*
- Maintains existing directory structure within categories
- Updates bruno/user/auth files with OAuth2 refresh token flow
- Updates bruno/user/profile files for user profile management
- Adds bruno/dashboard/ directory with dashboard API tests
- Preserves all existing test scenarios and OpenCollection YAML format
- No functional changes - file reorganization only

bruno/opds/Download Book KEPUB.yml

@@ -0,0 +1,7 @@
+info:
+  name: Download Book (KEPUB)
+  type: http
+  seq: 4
+http:
+  method: GET
+  url: '{{opds_base_url}}/devices/{{device_id}}/download/{{book_id}}?format=kepub'