为所有函数和类添加中文注释文档字符串

tests/test_ice_parser.py

@@ -2,9 +2,11 @@ from __future__ import annotations
 
 from app.signaling.ice_parser import parse_ice
 
-
 class TestIceParser:
+    """ICE候选者解析单元测试"""
+
     def test_parse_valid_ice(self):
+        """测试：解析有效的ICE host候选者"""
         data = {
             "candidate": "1234567890 1 UDP 2130706431 192.168.1.1 12345 typ host",
             "sdpMid": "0",
@@ -20,9 +22,11 @@ class TestIceParser:
         assert cand.type == "host"
 
     def test_parse_invalid_ice(self):
+        """测试：解析无效ICE字符串应返回None"""
         assert parse_ice({"candidate": "invalid"}) is None
 
     def test_parse_srflx(self):
+        """测试：解析含有raddr/rport的srflx候选者"""
         data = {
             "candidate": "abcdef 1 UDP 1686052607 203.0.113.1 50000 typ srflx raddr 192.168.1.1 rport 12345",
             "sdpMid": "0",