feat: panel UI'ını Tailwind v4 + shadcn/ui ile yeniden tasarla (Faz 4)

Elle yazılmış tek-dosya CSS (sabit koyu tema, ham table/button, window.confirm
ile silme onayı) yerine tutarlı bir bileşen sistemi: Card/Table/Badge/Button/
Input/Switch/AlertDialog primitifleri, Hanken Grotesk + JetBrains Mono
tipografi çifti, "broadcast/monitör" temalı özel bir renk paleti (camgöbeği
accent, ok/warn/err/live durum rengi sözlüğü). Tüm sayfalar (dashboard, kanal
detay, segmentler, ayarlar, istatistik, kullanıcılar, login) aynı oturumda
taşındı — silme onayları artık gerçek AlertDialog, native confirm() değil.

Veri akışı/server action'lar değişmedi, tamamen görsel katman.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/frontend/components/ui/switch.tsx

@@ -0,0 +1,35 @@
+"use client";
+
+import * as React from "react";
+import { Switch as SwitchPrimitive } from "radix-ui";
+
+import { cn } from "@/lib/utils";
+
+function Switch({
+  className,
+  size = "default",
+  ...props
+}: React.ComponentProps<typeof SwitchPrimitive.Root> & {
+  size?: "sm" | "default";
+}) {
+  return (
+    <SwitchPrimitive.Root
+      data-slot="switch"
+      data-size={size}
+      className={cn(
+        "peer group/switch inline-flex shrink-0 items-center rounded-full border border-transparent shadow-xs transition-all outline-none focus-visible:border-ring focus-visible:ring-[3px] focus-visible:ring-ring/50 disabled:cursor-not-allowed disabled:opacity-50 data-[size=default]:h-[1.15rem] data-[size=default]:w-8 data-[size=sm]:h-3.5 data-[size=sm]:w-6 data-[state=checked]:bg-primary data-[state=unchecked]:bg-input dark:data-[state=unchecked]:bg-input/80",
+        className,
+      )}
+      {...props}
+    >
+      <SwitchPrimitive.Thumb
+        data-slot="switch-thumb"
+        className={cn(
+          "pointer-events-none block rounded-full bg-background ring-0 transition-transform group-data-[size=default]/switch:size-4 group-data-[size=sm]/switch:size-3 data-[state=checked]:translate-x-[calc(100%-2px)] data-[state=unchecked]:translate-x-0 dark:data-[state=checked]:bg-primary-foreground dark:data-[state=unchecked]:bg-foreground",
+        )}
+      />
+    </SwitchPrimitive.Root>
+  );
+}
+
+export { Switch };