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/components/login-page.tsx

@@ -0,0 +1,100 @@
+import { useMutation } from "@tanstack/react-query"
+import { useState } from "react"
+import { Loader2, Settings2 } from "lucide-react"
+import { toast } from "sonner"
+
+import type { AuthSession } from "@/lib/auth"
+import { signIn } from "@/lib/auth"
+import { getServerUrl, setServerUrl } from "@/lib/server-url"
+
+import { Button } from "@/components/ui/button"
+import { Card, CardContent, CardDescription, CardHeader, CardTitle } from "@/components/ui/card"
+import { Input } from "@/components/ui/input"
+import { Label } from "@/components/ui/label"
+
+interface LoginPageProps {
+  onLogin: (session: AuthSession) => void
+}
+
+export function LoginPage({ onLogin }: LoginPageProps) {
+  const [serverUrlInput, setServerUrlInput] = useState(getServerUrl)
+  const [email, setEmail] = useState("")
+  const [password, setPassword] = useState("")
+
+  const loginMutation = useMutation({
+    mutationFn: async () => {
+      setServerUrl(serverUrlInput)
+      return signIn(email, password)
+    },
+    onSuccess(session) {
+      onLogin(session)
+    },
+    onError(err) {
+      toast.error(err.message)
+    },
+  })
+
+  function handleSubmit(e: React.FormEvent) {
+    e.preventDefault()
+    loginMutation.mutate()
+  }
+
+  const loading = loginMutation.isPending
+
+  return (
+    <div className="flex min-h-svh items-center justify-center bg-background p-4">
+      <Card className="w-full max-w-sm">
+        <CardHeader className="text-center">
+          <div className="mx-auto mb-2 flex size-10 items-center justify-center rounded-lg bg-primary/10">
+            <Settings2 className="size-5 text-primary" />
+          </div>
+          <CardTitle>Admin Dashboard</CardTitle>
+          <CardDescription>Sign in to manage source configuration.</CardDescription>
+        </CardHeader>
+        <CardContent>
+          <form onSubmit={handleSubmit} className="space-y-4">
+            <div className="space-y-2">
+              <Label htmlFor="server-url">Server URL</Label>
+              <Input
+                id="server-url"
+                type="url"
+                value={serverUrlInput}
+                onChange={(e) => setServerUrlInput(e.target.value)}
+                placeholder="http://localhost:3000"
+                required
+              />
+            </div>
+            <div className="space-y-2">
+              <Label htmlFor="email">Email</Label>
+              <Input
+                id="email"
+                type="email"
+                value={email}
+                onChange={(e) => setEmail(e.target.value)}
+                placeholder="admin@aelis.local"
+                required
+              />
+            </div>
+            <div className="space-y-2">
+              <Label htmlFor="password">Password</Label>
+              <Input
+                id="password"
+                type="password"
+                value={password}
+                onChange={(e) => setPassword(e.target.value)}
+                required
+              />
+            </div>
+
+
+            <Button type="submit" className="w-full" disabled={loading}>
+              {loading && <Loader2 className="size-4 animate-spin" />}
+              {loading ? "Signing in…" : "Sign in"}
+            </Button>
+
+          </form>
+        </CardContent>
+      </Card>
+    </div>
+  )
+}