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/ui/badge.tsx

@@ -0,0 +1,49 @@
+import * as React from "react"
+import { cva, type VariantProps } from "class-variance-authority"
+import { Slot } from "radix-ui"
+
+import { cn } from "@/lib/utils"
+
+const badgeVariants = cva(
+  "group/badge inline-flex h-5 w-fit shrink-0 items-center justify-center gap-1 overflow-hidden rounded-full border border-transparent px-2 py-0.5 text-[0.625rem] font-medium whitespace-nowrap transition-all focus-visible:border-ring focus-visible:ring-[3px] focus-visible:ring-ring/50 has-data-[icon=inline-end]:pr-1.5 has-data-[icon=inline-start]:pl-1.5 aria-invalid:border-destructive aria-invalid:ring-destructive/20 dark:aria-invalid:ring-destructive/40 [&>svg]:pointer-events-none [&>svg]:size-2.5!",
+  {
+    variants: {
+      variant: {
+        default: "bg-primary text-primary-foreground [a]:hover:bg-primary/80",
+        secondary:
+          "bg-secondary text-secondary-foreground [a]:hover:bg-secondary/80",
+        destructive:
+          "bg-destructive/10 text-destructive focus-visible:ring-destructive/20 dark:bg-destructive/20 dark:focus-visible:ring-destructive/40 [a]:hover:bg-destructive/20",
+        outline:
+          "border-border bg-input/20 text-foreground dark:bg-input/30 [a]:hover:bg-muted [a]:hover:text-muted-foreground",
+        ghost:
+          "hover:bg-muted hover:text-muted-foreground dark:hover:bg-muted/50",
+        link: "text-primary underline-offset-4 hover:underline",
+      },
+    },
+    defaultVariants: {
+      variant: "default",
+    },
+  }
+)
+
+function Badge({
+  className,
+  variant = "default",
+  asChild = false,
+  ...props
+}: React.ComponentProps<"span"> &
+  VariantProps<typeof badgeVariants> & { asChild?: boolean }) {
+  const Comp = asChild ? Slot.Root : "span"
+
+  return (
+    <Comp
+      data-slot="badge"
+      data-variant={variant}
+      className={cn(badgeVariants({ variant }), className)}
+      {...props}
+    />
+  )
+}
+
+export { Badge, badgeVariants }