Add Next.js frontend PWA

- Pages: login, register, tasks list, task detail
- Components: TaskCard, TaskForm, GroupSelector, StatusBadge, Header
- Tailwind CSS, dark/light mode, PWA manifest
- Running on :3001 via systemd

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/tasks/components/AuthProvider.tsx

@@ -0,0 +1,42 @@
+"use client";
+
+import { useState, useEffect, ReactNode } from "react";
+import { AuthContext, getStoredToken, getStoredUser, setStoredToken, setStoredUser } from "@/lib/auth";
+import { User } from "@/lib/api";
+
+export default function AuthProvider({ children }: { children: ReactNode }) {
+  const [token, setToken] = useState<string | null>(null);
+  const [user, setUser] = useState<User | null>(null);
+  const [loaded, setLoaded] = useState(false);
+
+  useEffect(() => {
+    setToken(getStoredToken());
+    setUser(getStoredUser());
+    setLoaded(true);
+  }, []);
+
+  function setAuth(newToken: string | null, newUser: User | null) {
+    setToken(newToken);
+    setUser(newUser);
+    setStoredToken(newToken);
+    setStoredUser(newUser);
+  }
+
+  function logout() {
+    setAuth(null, null);
+  }
+
+  if (!loaded) {
+    return (
+      <div className="min-h-screen flex items-center justify-center">
+        <div className="animate-spin rounded-full h-8 w-8 border-b-2 border-blue-600"></div>
+      </div>
+    );
+  }
+
+  return (
+    <AuthContext.Provider value={{ token, user, setAuth, logout }}>
+      {children}
+    </AuthContext.Provider>
+  );
+}