docs: rewrite README and AGENTS.md, add admin sync button

frontend/src/components/AdminTab.tsx

@@ -64,6 +64,26 @@ export default function AdminTab() {
     }
   }
 
+  async function onSync() {
+    setError("");
+    setInfo("");
+    try {
+      const r = await api.syncFlows();
+      const parts = [
+        `+${r.added.length}`,
+        `~${r.updated.length}`,
+        `-${r.deleted.length}`,
+      ].join(" ");
+      const errs = Object.entries(r.errors)
+        .map(([f, e]) => `${f}: ${e}`)
+        .join("; ");
+      setInfo(`Sync ${parts}${errs ? ` — Fehler: ${errs}` : ""}`);
+      await load();
+    } catch (e) {
+      setError(e instanceof ApiError ? `${e.status}: ${e.message}` : String(e));
+    }
+  }
+
   return (
     <div>
       <h2>Administration</h2>
@@ -93,11 +113,19 @@ export default function AdminTab() {
         </button>
       </div>
       <h3>Flows + Versionen</h3>
+      <div style={{ marginBottom: 12 }}>
+        <button onClick={() => void onSync()}>
+          Aus backend/flows synchronisieren
+        </button>
+      </div>
       {flows.length === 0 && <p>Keine Flows vorhanden.</p>}
       <ul>
         {flows.map((f) => (
           <li key={f.id} style={{ marginBottom: 8 }}>
-            <strong>{f.name}</strong>
+            <strong>{f.name}</strong>{" "}
+            <span style={{ fontFamily: "monospace", fontSize: "0.85em" }}>
+              {f.source_path ? `(${f.source_path})` : "(API)"}
+            </span>
             <ul>
               {(versions[f.id] ?? []).map((v) => (
                 <li key={v.id}>