feat: add TagsPage component and integrate it into the main application

frontend/src/App.tsx

@@ -4,6 +4,7 @@ import { getSeed, getTrips, getNextTripId } from "./api";
 import ItemsPage from "./pages/ItemsPage";
 import TripChecklist from "./pages/TripChecklist";
 import TripsPage from "./pages/TripsPage";
+import TagsPage from "./pages/TagsPage";
 
 function NextTripRedirect({ trips }: { trips: any[] }) {
   const [nextTripId, setNextTripId] = React.useState<string | null>(null);
@@ -55,12 +56,17 @@ export default function App() {
         </button>
         <Link to="/trips">
           <button className="bg-blue-500 text-white px-4 py-2 rounded">
-            Alle Trips
+            Trips
           </button>
         </Link>
         <Link to="/items">
           <button className="bg-green-500 text-white px-4 py-2 rounded">
-            Alle Items
+            Items
+          </button>
+        </Link>
+        <Link to="/tags">
+          <button className="bg-purple-500 text-white px-4 py-2 rounded">
+            Tags
           </button>
         </Link>
         <button
@@ -78,6 +84,7 @@ export default function App() {
         <Route path="/trips" element={<TripsPage />} />
         <Route path="/trips/:id" element={<TripChecklist trips={trips} />} />
         <Route path="/items" element={<ItemsPage />} />
+        <Route path="/tags" element={<TagsPage />} />
         <Route path="/" element={<NextTripRedirect trips={trips} />} />
       </Routes>
     </div>

frontend/src/pages/TagsPage.tsx

@@ -0,0 +1,151 @@
+import React, { useEffect, useState } from "react";
+import { getTags } from "../api";
+import type { Tag } from "../api";
+
+const API_BASE = "http://localhost:8000";
+
+export default function TagsPage() {
+  const [tags, setTags] = useState<Tag[]>([]);
+  const [editingId, setEditingId] = useState<string | null>(null);
+  const [editName, setEditName] = useState("");
+  const [editMandatory, setEditMandatory] = useState(false);
+  const [newName, setNewName] = useState("");
+  const [newMandatory, setNewMandatory] = useState(false);
+
+  async function loadTags() {
+    setTags(await getTags());
+  }
+
+  useEffect(() => {
+    loadTags();
+  }, []);
+
+  async function handleSave(id: string) {
+    await fetch(`${API_BASE}/tags/${id}`, {
+      method: "PUT",
+      headers: { "Content-Type": "application/json" },
+      body: JSON.stringify({ name: editName, mandatory: editMandatory }),
+    });
+    setEditingId(null);
+    await loadTags();
+  }
+
+  async function handleDelete(id: string) {
+    if (!window.confirm("Tag wirklich löschen?")) return;
+    await fetch(`${API_BASE}/tags/${id}`, { method: "DELETE" });
+    await loadTags();
+  }
+
+  async function handleCreate(e: React.FormEvent) {
+    e.preventDefault();
+    await fetch(`${API_BASE}/tags/`, {
+      method: "POST",
+      headers: { "Content-Type": "application/json" },
+      body: JSON.stringify({ name: newName, mandatory: newMandatory }),
+    });
+    setNewName("");
+    setNewMandatory(false);
+    await loadTags();
+  }
+
+  return (
+    <div className="p-4 max-w-xl mx-auto">
+      <h1 className="text-2xl font-bold mb-4">Alle Tags</h1>
+      <form className="flex gap-2 mb-6" onSubmit={handleCreate}>
+        <input
+          className="border rounded px-2 py-1 flex-1"
+          placeholder="Neuer Tag..."
+          value={newName}
+          onChange={e => setNewName(e.target.value)}
+          required
+        />
+        <label className="flex items-center gap-1 text-sm">
+          <input
+            type="checkbox"
+            checked={newMandatory}
+            onChange={e => setNewMandatory(e.target.checked)}
+          />
+          mandatory
+        </label>
+        <button
+          className="bg-green-500 text-white px-3 py-1 rounded"
+          type="submit"
+        >
+          Hinzufügen
+        </button>
+      </form>
+      <ul>
+        {tags.map(tag =>
+          editingId === tag.id ? (
+            <li key={tag.id} className="flex gap-2 items-center mb-2">
+              <input
+                className="border rounded px-2 py-1 flex-1"
+                value={editName}
+                onChange={e => setEditName(e.target.value)}
+              />
+              <label className="flex items-center gap-1 text-sm">
+                <input
+                  type="checkbox"
+                  checked={editMandatory}
+                  onChange={e => setEditMandatory(e.target.checked)}
+                />
+                mandatory
+              </label>
+              <button
+                className="bg-blue-500 text-white px-2 py-1 rounded"
+                onClick={() => handleSave(tag.id)}
+                type="button"
+              >
+                Speichern
+              </button>
+              <button
+                className="bg-gray-300 px-2 py-1 rounded"
+                onClick={() => setEditingId(null)}
+                type="button"
+              >
+                Abbrechen
+              </button>
+            </li>
+          ) : (
+            <li
+              key={tag.id}
+              className="flex gap-2 items-center mb-2 group"
+            >
+              <span
+                className={
+                  "px-2 py-0.5 rounded text-sm " +
+                  (tag.mandatory
+                    ? "border-2 border-yellow-400 bg-yellow-50 font-bold"
+                    : "bg-gray-100")
+                }
+              >
+                #{tag.name}
+                {tag.mandatory && (
+                  <span className="ml-1 text-yellow-500 font-bold">*</span>
+                )}
+              </span>
+              <button
+                className="text-xs text-blue-500 underline"
+                onClick={() => {
+                  setEditingId(tag.id);
+                  setEditName(tag.name);
+                  setEditMandatory(tag.mandatory);
+                }}
+                type="button"
+              >
+                Bearbeiten
+              </button>
+              <button
+                className="text-xs text-red-500 underline opacity-0 group-hover:opacity-100"
+                onClick={() => handleDelete(tag.id)}
+                type="button"
+              >
+                Löschen
+              </button>
+            </li>
+          )
+        )}
+      </ul>
+    </div>
+  );
+}