feat(lite): add opt-in tun ipv6 mode

lite/rrpp_core/socks_bridge.py

@@ -587,6 +587,20 @@ class Socks5Bridge:
         except OSError:
             pass
 
+    def _proxy_target(self, target: Address) -> Address:
+        """为上游 CONNECT 恢复唯一 DNS 域名，给 IPv6 目标提供 IPv4 回退。"""
+        try:
+            ipaddress.ip_address(target.host)
+        except ValueError:
+            return target
+        domain = self._dns.lookup_ip(target.host)
+        if not domain:
+            return target
+        self.log(
+            f"[桥接] IPv6 目标回退域名解析: {target.host} -> {domain}:{target.port}"
+        )
+        return Address(domain, target.port)
+
     def _open_target(self, target: Address) -> socket.socket:
         policy_host = self._policy_host(target.host)
         rule = self._route_rule(policy_host, target.host)
@@ -594,12 +608,12 @@ class Socks5Bridge:
         if rule and str(rule.get("action") or "").lower() == "node":
             if route_node is None:
                 raise ConnectionError("域名路由指定的节点不可用")
-            return self._dialer(route_node).open(target)
+            return self._dialer(route_node).open(self._proxy_target(target))
         direct = self._direct_target_for(target.host, target.port, policy_host)
         if direct is not None:
             self._ensure_direct_routes(direct[0], direct[1])
             return socket.create_connection(direct, 15)
-        return self._dialer(self.node).open(target)
+        return self._dialer(self.node).open(self._proxy_target(target))
 
     def _tcp(self, client: socket.socket, target: Address):
         upstream = self._open_target(target)