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/collections/Create Collection.yml

@@ -0,0 +1,15 @@
+info:
+  name: Create Collection
+  type: http
+  seq: 1
+http:
+  method: POST
+  url: '{{base_url}}/api/collections'
+  auth: inherit
+  body:
+    type: json
+    jsonBody: "{\n    \"name\": \"Science Fiction\",\n    \"description\": \"My favorite\
+      \ sci-fi books\",\n    \"color\": \"#ff0000\",\n    \"icon\": \"\U0001F680\"\
+      ,\n    \"auto_assign_rules\": [\n      {\n        \"id\": \"rule-1\",\n    \
+      \    \"field\": \"genre\",\n        \"operator\": \"equals\",\n        \"value\"\
+      : \"Science Fiction\",\n        \"priority\": 8"