Feature: Konfig-Export/Import im Web UI (Einstellungen-Tab)

- GET /api/export-config → JSON-Download mit allen Geräten + MQTT (ohne Passwort)
- POST /api/import-config → Validierung + Übernahme + automatischer Neustart
- Einstellungen-Tab: Exportieren-Button + Importieren-Dateiauswahl
- btn-secondary CSS-Klasse hinzugefügt

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

haos-addon/src/main.py

@@ -355,6 +355,59 @@ def api_get_models():
 def api_new_id():
     return jsonify({"id": uuid.uuid4().hex[:8]})
 
+
+@app.get("/api/export-config")
+def api_export_config():
+    with State.lock:
+        data = {
+            "shinebridge_export": True,
+            "version": 1,
+            "exported_at": time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime()),
+            "mqtt": {
+                "broker": State.mqtt_cfg.get("mqtt_broker", ""),
+                "port":   State.mqtt_cfg.get("mqtt_port", 1883),
+                "user":   State.mqtt_cfg.get("mqtt_user", ""),
+            },
+            "inverters": State.inverters_cfg,
+        }
+    from flask import Response
+    filename = f"shinebridge-config-{time.strftime('%Y%m%d-%H%M%S')}.json"
+    return Response(
+        json.dumps(data, indent=2, ensure_ascii=False),
+        mimetype="application/json",
+        headers={"Content-Disposition": f'attachment; filename="{filename}"'},
+    )
+
+
+@app.post("/api/import-config")
+def api_import_config():
+    data = request.get_json(force=True) or {}
+    if not data.get("shinebridge_export"):
+        return jsonify({"error": "Keine gültige ShineBridge-Export-Datei"}), 400
+
+    inverters = data.get("inverters", [])
+    if not isinstance(inverters, list):
+        return jsonify({"error": "inverters ungültig"}), 400
+    for inv in inverters:
+        if not inv.get("modbus_ip"):
+            return jsonify({"error": f"modbus_ip fehlt in Gerät {inv.get('name', '?')}"}), 400
+        if inv.get("inverter_model") not in INVERTERS:
+            return jsonify({"error": f"Unbekanntes Modell: {inv.get('inverter_model')}"}), 400
+
+    with State.lock:
+        if mqtt := data.get("mqtt"):
+            if mqtt.get("broker"):
+                State.mqtt_cfg["mqtt_broker"] = mqtt["broker"]
+            if mqtt.get("port"):
+                State.mqtt_cfg["mqtt_port"] = int(mqtt["port"])
+            if mqtt.get("user"):
+                State.mqtt_cfg["mqtt_user"] = mqtt["user"]
+        State.inverters_cfg = inverters
+        save_config()
+
+    threading.Thread(target=_restart_all, daemon=True).start()
+    return jsonify({"ok": True, "inverters": len(inverters)})
+
 @app.get("/")
 def index():
     return send_from_directory(WEB_DIR, "index.html")