feat: refactor agent manager, media library, and player UX

- Split admin users page into player/tier-1/tier-2 tabs with affiliation labels and context-specific create dialogs

- Add media library with uploaded_files migration, list/delete unused files API, and admin nav route

- Enforce player username format (alphanumeric 3-32) on frontend and backend via shared package

- Improve admin dialog/panel styling; refine player parlay and match bet card kickoff display

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/admin/src/router/index.ts

@@ -87,8 +87,8 @@ const router = createRouter({
           meta: { adminOnly: true },
         },
         {
-          path: 'smoke-tests',
-          component: () => import('../views/SmokeTests.vue'),
+          path: 'media',
+          component: () => import('../views/MediaLibrary.vue'),
           meta: { adminOnly: true },
         },
         {