feat: implement authentication context and hooks for user management

- Add AuthContext to manage user authentication state and token storage.
- Create hooks for login, registration, and logout functionalities.
- Implement dashboard layout with authentication check and loading state.
- Enhance dashboard page with channel management features including create, edit, and delete channels.
- Integrate API calls for channel operations and current broadcast retrieval.
- Add stream URL resolution via server-side API route to handle redirects.
- Update TV page to utilize new hooks for channel and broadcast management.
- Refactor components for better organization and user experience.
- Update application metadata for improved branding.

k-tv-frontend/app/api/stream/[channelId]/route.ts

@@ -0,0 +1,56 @@
+import { NextRequest } from "next/server";
+
+// Server-side URL of the K-TV backend (never exposed to the browser).
+// Falls back to the public URL if the internal one isn't set.
+const API_URL =
+  process.env.API_URL ??
+  process.env.NEXT_PUBLIC_API_URL ??
+  "http://localhost:4000/api/v1";
+
+/**
+ * GET /api/stream/[channelId]?token=<bearer>
+ *
+ * Resolves the backend's 307 stream redirect and returns the final
+ * Jellyfin URL as JSON. Browsers can't read the Location header from a
+ * redirected fetch, so this server-side route does it for them.
+ *
+ * Returns:
+ *   200 { url: string }  — stream URL ready to use as <video src>
+ *   204                  — channel is in a gap (no-signal)
+ *   401                  — missing token
+ *   502                  — backend error
+ */
+export async function GET(
+  request: NextRequest,
+  { params }: { params: Promise<{ channelId: string }> },
+) {
+  const { channelId } = await params;
+  const token = request.nextUrl.searchParams.get("token");
+
+  if (!token) {
+    return new Response(null, { status: 401 });
+  }
+
+  let res: Response;
+  try {
+    res = await fetch(`${API_URL}/channels/${channelId}/stream`, {
+      headers: { Authorization: `Bearer ${token}` },
+      redirect: "manual",
+    });
+  } catch {
+    return new Response(null, { status: 502 });
+  }
+
+  if (res.status === 204) {
+    return new Response(null, { status: 204 });
+  }
+
+  if (res.status === 307 || res.status === 302 || res.status === 301) {
+    const location = res.headers.get("Location");
+    if (location) {
+      return Response.json({ url: location });
+    }
+  }
+
+  return new Response(null, { status: 502 });
+}