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/app/register/page.tsx

@@ -0,0 +1,108 @@
+"use client";
+
+import { useState } from "react";
+import { useRouter } from "next/navigation";
+import Link from "next/link";
+import { register } from "@/lib/api";
+import { useAuth } from "@/lib/auth";
+
+export default function RegisterPage() {
+  const [email, setEmail] = useState("");
+  const [name, setName] = useState("");
+  const [phone, setPhone] = useState("");
+  const [loading, setLoading] = useState(false);
+  const [error, setError] = useState("");
+  const { setAuth } = useAuth();
+  const router = useRouter();
+
+  async function handleSubmit(e: React.FormEvent) {
+    e.preventDefault();
+    if (!email.trim() || !name.trim()) {
+      setError("Email a jmeno jsou povinne");
+      return;
+    }
+    setLoading(true);
+    setError("");
+    try {
+      const result = await register({
+        email: email.trim(),
+        name: name.trim(),
+        phone: phone.trim() || undefined,
+      });
+      setAuth(result.token, result.user);
+      router.push("/tasks");
+    } catch (err) {
+      setError(err instanceof Error ? err.message : "Chyba registrace");
+    } finally {
+      setLoading(false);
+    }
+  }
+
+  return (
+    <div className="min-h-[70vh] flex items-center justify-center">
+      <div className="w-full max-w-sm">
+        <div className="bg-white dark:bg-gray-900 border border-gray-200 dark:border-gray-700 rounded-2xl p-6 shadow-sm">
+          <h1 className="text-2xl font-bold text-center mb-6">Registrace</h1>
+
+          {error && (
+            <div className="bg-red-50 dark:bg-red-900/20 border border-red-200 dark:border-red-800 text-red-700 dark:text-red-300 px-4 py-3 rounded-lg text-sm mb-4">
+              {error}
+            </div>
+          )}
+
+          <form onSubmit={handleSubmit} className="space-y-4">
+            <div>
+              <label className="block text-sm font-medium mb-1">Jmeno *</label>
+              <input
+                type="text"
+                value={name}
+                onChange={(e) => setName(e.target.value)}
+                className="w-full px-3 py-2.5 border border-gray-300 dark:border-gray-600 rounded-lg bg-white dark:bg-gray-800 focus:ring-2 focus:ring-blue-500 focus:border-transparent outline-none"
+                placeholder="Vase jmeno"
+                autoFocus
+              />
+            </div>
+
+            <div>
+              <label className="block text-sm font-medium mb-1">Email *</label>
+              <input
+                type="email"
+                value={email}
+                onChange={(e) => setEmail(e.target.value)}
+                className="w-full px-3 py-2.5 border border-gray-300 dark:border-gray-600 rounded-lg bg-white dark:bg-gray-800 focus:ring-2 focus:ring-blue-500 focus:border-transparent outline-none"
+                placeholder="vas@email.cz"
+                autoComplete="email"
+              />
+            </div>
+
+            <div>
+              <label className="block text-sm font-medium mb-1">Telefon</label>
+              <input
+                type="tel"
+                value={phone}
+                onChange={(e) => setPhone(e.target.value)}
+                className="w-full px-3 py-2.5 border border-gray-300 dark:border-gray-600 rounded-lg bg-white dark:bg-gray-800 focus:ring-2 focus:ring-blue-500 focus:border-transparent outline-none"
+                placeholder="+420 123 456 789"
+              />
+            </div>
+
+            <button
+              type="submit"
+              disabled={loading}
+              className="w-full bg-blue-600 hover:bg-blue-700 text-white font-medium py-2.5 px-4 rounded-lg transition-colors disabled:opacity-50"
+            >
+              {loading ? "Registruji..." : "Registrovat se"}
+            </button>
+          </form>
+
+          <p className="text-center text-sm text-muted mt-4">
+            Jiz mate ucet?{" "}
+            <Link href="/login" className="text-blue-600 hover:underline">
+              Prihlasit se
+            </Link>
+          </p>
+        </div>
+      </div>
+    </div>
+  );
+}