fix(wechat): Windows 系统上 doctor 误判微信公众号渠道不可用 (#263)

fix(wechat): Windows GBK encoding causes false negative in doctor check

agent_reach/channels/wechat.py

@@ -17,7 +17,7 @@ def _exa_available() -> bool:
     try:
         r = subprocess.run(
             [mcporter, "config", "list"],
-            capture_output=True, text=True, timeout=5,
+            capture_output=True, encoding="utf-8", errors="replace", timeout=5,
         )
         return "exa" in r.stdout.lower()
     except Exception: