fix: add /cases/new route to prevent dynamic [id] catch

The static "new" segment was missing, so Next.js treated "new" as a
UUID parameter for [id]/page.tsx, causing a Postgres "invalid input
syntax for type uuid" error. Adding cases/new/page.tsx with a create
form resolves the server error.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

src/app/(dashboard)/cases/new/page.tsx

@@ -0,0 +1,215 @@
+'use client';
+
+import { useState } from 'react';
+import { useRouter } from 'next/navigation';
+import Link from 'next/link';
+
+export default function NewCasePage() {
+  const router = useRouter();
+  const [loading, setLoading] = useState(false);
+  const [error, setError] = useState('');
+
+  async function handleSubmit(e: React.FormEvent<HTMLFormElement>) {
+    e.preventDefault();
+    setError('');
+    setLoading(true);
+
+    const form = new FormData(e.currentTarget);
+    const body = {
+      caseNumber: form.get('caseNumber'),
+      title: form.get('title'),
+      description: form.get('description') || undefined,
+      clientName: form.get('clientName') || undefined,
+      opposingParty: form.get('opposingParty') || undefined,
+      venue: form.get('venue') || undefined,
+      status: form.get('status') || 'active',
+      filingDate: form.get('filingDate') || undefined,
+      hearingDate: form.get('hearingDate') || undefined,
+    };
+
+    try {
+      const res = await fetch('/api/cases', {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify(body),
+      });
+
+      if (!res.ok) {
+        const data = await res.json().catch(() => null);
+        throw new Error(data?.error ?? 'Fall konnte nicht angelegt werden.');
+      }
+
+      const data = await res.json();
+      router.push(`/cases/${data.case.id}`);
+    } catch (err) {
+      setError(err instanceof Error ? err.message : 'Ein Fehler ist aufgetreten.');
+      setLoading(false);
+    }
+  }
+
+  return (
+    <div className="space-y-6">
+      <div className="flex items-center gap-2 text-sm text-muted">
+        <Link href="/cases" className="hover:text-primary transition-colors">
+          Faelle
+        </Link>
+        <span>/</span>
+        <span>Neuer Fall</span>
+      </div>
+
+      <h1 className="text-xl font-bold text-foreground">Neuen Fall anlegen</h1>
+
+      {error && (
+        <div className="bg-red-50 border border-red-200 text-red-700 rounded-lg px-4 py-3 text-sm">
+          {error}
+        </div>
+      )}
+
+      <form onSubmit={handleSubmit} className="bg-card-bg border border-card-border rounded-xl p-6 space-y-4">
+        <div className="grid grid-cols-1 sm:grid-cols-2 gap-4">
+          <div>
+            <label htmlFor="caseNumber" className="block text-sm font-medium text-foreground mb-1">
+              Aktenzeichen *
+            </label>
+            <input
+              id="caseNumber"
+              name="caseNumber"
+              type="text"
+              required
+              placeholder="z.B. 2026/001"
+              className="w-full rounded-lg border border-card-border px-3 py-2.5 text-sm bg-white focus:outline-none focus:ring-2 focus:ring-primary/30 focus:border-primary"
+            />
+          </div>
+
+          <div>
+            <label htmlFor="title" className="block text-sm font-medium text-foreground mb-1">
+              Titel *
+            </label>
+            <input
+              id="title"
+              name="title"
+              type="text"
+              required
+              placeholder="Kurztitel des Falls"
+              className="w-full rounded-lg border border-card-border px-3 py-2.5 text-sm bg-white focus:outline-none focus:ring-2 focus:ring-primary/30 focus:border-primary"
+            />
+          </div>
+        </div>
+
+        <div>
+          <label htmlFor="description" className="block text-sm font-medium text-foreground mb-1">
+            Beschreibung
+          </label>
+          <textarea
+            id="description"
+            name="description"
+            rows={3}
+            placeholder="Optionale Beschreibung des Falls"
+            className="w-full rounded-lg border border-card-border px-3 py-2.5 text-sm bg-white focus:outline-none focus:ring-2 focus:ring-primary/30 focus:border-primary"
+          />
+        </div>
+
+        <div className="grid grid-cols-1 sm:grid-cols-2 gap-4">
+          <div>
+            <label htmlFor="clientName" className="block text-sm font-medium text-foreground mb-1">
+              Mandant
+            </label>
+            <input
+              id="clientName"
+              name="clientName"
+              type="text"
+              placeholder="Name des Mandanten"
+              className="w-full rounded-lg border border-card-border px-3 py-2.5 text-sm bg-white focus:outline-none focus:ring-2 focus:ring-primary/30 focus:border-primary"
+            />
+          </div>
+
+          <div>
+            <label htmlFor="opposingParty" className="block text-sm font-medium text-foreground mb-1">
+              Gegenseite
+            </label>
+            <input
+              id="opposingParty"
+              name="opposingParty"
+              type="text"
+              placeholder="Name der Gegenseite"
+              className="w-full rounded-lg border border-card-border px-3 py-2.5 text-sm bg-white focus:outline-none focus:ring-2 focus:ring-primary/30 focus:border-primary"
+            />
+          </div>
+        </div>
+
+        <div className="grid grid-cols-1 sm:grid-cols-3 gap-4">
+          <div>
+            <label htmlFor="venue" className="block text-sm font-medium text-foreground mb-1">
+              Buehne / Spielstaette
+            </label>
+            <input
+              id="venue"
+              name="venue"
+              type="text"
+              placeholder="z.B. Staatsoper Berlin"
+              className="w-full rounded-lg border border-card-border px-3 py-2.5 text-sm bg-white focus:outline-none focus:ring-2 focus:ring-primary/30 focus:border-primary"
+            />
+          </div>
+
+          <div>
+            <label htmlFor="status" className="block text-sm font-medium text-foreground mb-1">
+              Status
+            </label>
+            <select
+              id="status"
+              name="status"
+              defaultValue="active"
+              className="w-full rounded-lg border border-card-border px-3 py-2.5 text-sm bg-white focus:outline-none focus:ring-2 focus:ring-primary/30 focus:border-primary"
+            >
+              <option value="active">Aktiv</option>
+              <option value="closed">Abgeschlossen</option>
+              <option value="archived">Archiviert</option>
+            </select>
+          </div>
+        </div>
+
+        <div className="grid grid-cols-1 sm:grid-cols-2 gap-4">
+          <div>
+            <label htmlFor="filingDate" className="block text-sm font-medium text-foreground mb-1">
+              Eingereicht am
+            </label>
+            <input
+              id="filingDate"
+              name="filingDate"
+              type="date"
+              className="w-full rounded-lg border border-card-border px-3 py-2.5 text-sm bg-white focus:outline-none focus:ring-2 focus:ring-primary/30 focus:border-primary"
+            />
+          </div>
+
+          <div>
+            <label htmlFor="hearingDate" className="block text-sm font-medium text-foreground mb-1">
+              Verhandlungstermin
+            </label>
+            <input
+              id="hearingDate"
+              name="hearingDate"
+              type="date"
+              className="w-full rounded-lg border border-card-border px-3 py-2.5 text-sm bg-white focus:outline-none focus:ring-2 focus:ring-primary/30 focus:border-primary"
+            />
+          </div>
+        </div>
+
+        <div className="flex items-center gap-3 pt-2">
+          <button
+            type="submit"
+            disabled={loading}
+            className="px-4 py-2.5 bg-primary text-white rounded-lg text-sm font-medium hover:bg-primary-light transition-colors disabled:opacity-50 disabled:cursor-not-allowed"
+          >
+            {loading ? 'Wird angelegt...' : 'Fall anlegen'}
+          </button>
+          <Link
+            href="/cases"
+            className="px-4 py-2.5 border border-card-border rounded-lg text-sm font-medium text-muted hover:text-foreground transition-colors"
+          >
+            Abbrechen
+          </Link>
+        </div>
+      </form>
+    </div>
+  );
+}