add boltz fee dynamically

lnbits/extensions/boltz/templates/boltz/_api_docs.html

@@ -39,8 +39,9 @@
       <b>Fee Information</b>
     </h3>
     <span>
-      Every swap consists of 2 onchain transactions, lockup and claim / refund,
-      routing fees and a Boltz fee of <b>0.5%</b>.
+      {% raw %} Every swap consists of 2 onchain transactions, lockup and claim
+      / refund, routing fees and a Boltz fee of
+      <b>{{ boltzConfig.fee_percentage }}%</b>. {% endraw %}
     </span>
   </q-card-section>
   <q-expansion-item

lnbits/extensions/boltz/views_api.py

@@ -325,4 +325,8 @@ async def api_swap_status(swap_id: str):
 )
 async def api_boltz_config():
     client = create_boltz_client()
-    return {"minimal": client.limit_minimal, "maximal": client.limit_maximal}
+    return {
+        "minimal": client.limit_minimal,
+        "maximal": client.limit_maximal,
+        "fee_percentage": client.fee_percentage,
+    }