fix(ui): improve responsive layouts and refine API access page

- Fix overflow, clipped controls, and toolbar overlap in narrow windows
- Improve responsive layouts across usage, OAuth, agents, settings, and dialogs
- Unify API category navigation and compact provider rows and actions
- Preserve inherited provider priorities instead of displaying zero
- Add responsive layout regression tests and dense provider fixtures
- Bump proxy core version from 8.0.6 to 8.0.10

package.json

@@ -10,6 +10,8 @@
     "preview": "vite preview",
     "test:ui:accessibility": "node tests/app-shell-accessibility-ui.cjs",
     "test:ui:api-provider-dialog": "node tests/api-provider-dialog-layout-ui.cjs",
+    "test:ui:api-access-layout": "node tests/api-access-layout-ui.cjs",
+    "test:ui:responsive": "node tests/responsive-layout-ui.cjs",
     "screenshots": "node scripts/capture-readme-screenshots.cjs",
     "tauri": "tauri"
   },