feat: migrate frontend to Astro + expand AI moderation + backend admin/runtime config

Frontend:
- migrate from Vite to Astro (astro.config.mjs, pages/, layouts/)
- add admin panel, settings page, command palette, error boundary
- refactor App.tsx, MascotChatbot, Sidebar, Header, DashboardLayout
- update API client, WebSocket, auth, dashboard features

Backend:
- add admin module and config routes
- refactor middlewares, Redis connection, WebSocket server/bridge
- add runtime config loader

Discord Gateway:
- refactor AI moderation: circuit breaker, concurrency limiter, fallback processor
- add media analysis client, Seaxng search, user profile learner
- add new drizzle migration

Shared:
- extend database schema, add new config fields

services/frontend/.astro/dev.json

@@ -0,0 +1,18 @@
+{
+	"pid": 866059,
+	"port": 3000,
+	"url": "http://localhost:3000",
+	"urls": {
+		"local": [
+			"http://localhost:3000/"
+		],
+		"network": [
+			"http://192.168.1.65:3000/",
+			"http://100.114.19.66:3000/",
+			"http://172.27.0.1:3000/",
+			"http://172.26.0.1:3000/"
+		]
+	},
+	"background": false,
+	"startedAt": "2026-07-01T15:35:45.072Z"
+}