fix: add user field to frpc.ini for client identification

- frps assigns random clientID without user field
- Web UI matches clients by name, so all showed offline
- Now render_frpc_ini() writes user = <client-name>
- frps dashboard API returns user field for matching

app.py

@@ -501,6 +501,8 @@ def render_frpc_ini(client, server_addr, bind_port):
     lines.append("[common]")
     lines.append(f"server_addr = {server_addr}")
     lines.append(f"server_port = {bind_port}")
+    # Set user so frps identifies this client by name (for dashboard matching)
+    lines.append(f"user = {client.name}")
     lines.append("authentication_method = token")
     lines.append(f"token = {token}")
     # Admin API for `frpc reload` command