feat: add admin dashboard app (#91)

* feat: add admin dashboard app

- React + Vite + TanStack Router + TanStack Query
- Auth with better-auth (login, session, admin guard)
- Source config management (WeatherKit credentials, user config)
- Feed query panel
- Location push card
- General settings with health check
- CORS middleware for cross-origin auth
- Disable CSRF check in dev mode
- Sonner toasts for mutation feedback

Co-authored-by: Ona <no-reply@ona.com>

* fix: use useQuery instead of getQueryData

Co-authored-by: Ona <no-reply@ona.com>

* refactor: remove backend changes from dashboard PR

Backend CORS/CSRF changes moved to #92.
Source registry removed (sources hardcoded in frontend).

Co-authored-by: Ona <no-reply@ona.com>

---------

Co-authored-by: Ona <no-reply@ona.com>

apps/admin-dashboard/src/lib/auth.ts

@@ -0,0 +1,47 @@
+import { getServerUrl } from "./server-url"
+
+function authBase() {
+  return `${getServerUrl()}/api/auth`
+}
+
+export interface AuthUser {
+  id: string
+  name: string
+  email: string
+  image: string | null
+}
+
+export interface AuthSession {
+  user: AuthUser
+  session: { id: string; token: string }
+}
+
+export async function getSession(): Promise<AuthSession | null> {
+  const res = await fetch(`${authBase()}/get-session`, {
+    credentials: "include",
+  })
+  if (!res.ok) return null
+  const data = (await res.json()) as AuthSession | null
+  return data
+}
+
+export async function signIn(email: string, password: string): Promise<AuthSession> {
+  const res = await fetch(`${authBase()}/sign-in/email`, {
+    method: "POST",
+    headers: { "Content-Type": "application/json" },
+    credentials: "include",
+    body: JSON.stringify({ email, password }),
+  })
+  if (!res.ok) {
+    const data = (await res.json()) as { message?: string }
+    throw new Error(data.message ?? `Sign in failed: ${res.status}`)
+  }
+  return (await res.json()) as AuthSession
+}
+
+export async function signOut(): Promise<void> {
+  await fetch(`${authBase()}/sign-out`, {
+    method: "POST",
+    credentials: "include",
+  })
+}