fix: salvage follow-ups for Weixin adapter (#6747)

- Remove sys.path.insert hack (leftover from standalone dev)
- Add token lock (acquire_scoped_lock/release_scoped_lock) in
  connect()/disconnect() to prevent duplicate pollers across profiles
- Fix get_connected_platforms: WEIXIN check must precede generic
  token/api_key check (requires both token AND account_id)
- Add WEIXIN_HOME_CHANNEL_NAME to _EXTRA_ENV_KEYS
- Add gateway setup wizard with QR login flow
- Add platform status check for partially configured state
- Add weixin.md docs page with full adapter documentation
- Update environment-variables.md reference with all 11 env vars
- Update sidebars.ts to include weixin docs page
- Wire all gateway integration points onto current main

Salvaged from PR #6747 by Zihan Huang.

tools/send_message_tool.py

@@ -18,6 +18,7 @@ logger = logging.getLogger(__name__)
 
 _TELEGRAM_TOPIC_TARGET_RE = re.compile(r"^\s*(-?\d+)(?::(\d+))?\s*$")
 _FEISHU_TARGET_RE = re.compile(r"^\s*((?:oc|ou|on|chat|open)_[-A-Za-z0-9]+)(?::([-A-Za-z0-9_]+))?\s*$")
+_WEIXIN_TARGET_RE = re.compile(r"^\s*((?:wxid|gh|v\d+|wm|wb)_[A-Za-z0-9_-]+|[A-Za-z0-9._-]+@chatroom|filehelper)\s*$")
 # Discord snowflake IDs are numeric, same regex pattern as Telegram topic targets.
 _NUMERIC_TOPIC_RE = _TELEGRAM_TOPIC_TARGET_RE
 _IMAGE_EXTS = {".jpg", ".jpeg", ".png", ".webp", ".gif"}
@@ -157,6 +158,7 @@ def _handle_send(args):
         "dingtalk": Platform.DINGTALK,
         "feishu": Platform.FEISHU,
         "wecom": Platform.WECOM,
+        "weixin": Platform.WEIXIN,
         "email": Platform.EMAIL,
         "sms": Platform.SMS,
     }
@@ -237,6 +239,10 @@ def _parse_target_ref(platform_name: str, target_ref: str):
         match = _NUMERIC_TOPIC_RE.fullmatch(target_ref)
         if match:
             return match.group(1), match.group(2), True
+    if platform_name == "weixin":
+        match = _WEIXIN_TARGET_RE.fullmatch(target_ref)
+        if match:
+            return match.group(1), None, True
     if target_ref.lstrip("-").isdigit():
         return target_ref, None, True
     return None, None, False
@@ -369,6 +375,10 @@ async def _send_to_platform(platform, pconfig, chat_id, message, thread_id=None,
             last_result = result
         return last_result
 
+    # --- Weixin: use the native one-shot adapter helper for text + media ---
+    if platform == Platform.WEIXIN:
+        return await _send_weixin(pconfig, chat_id, message, media_files=media_files)
+
     # --- Non-Telegram platforms ---
     if media_files and not message.strip():
         return {
@@ -903,6 +913,27 @@ async def _send_wecom(extra, chat_id, message):
         return _error(f"WeCom send failed: {e}")
 
 
+async def _send_weixin(pconfig, chat_id, message, media_files=None):
+    """Send via Weixin iLink using the native adapter helper."""
+    try:
+        from gateway.platforms.weixin import check_weixin_requirements, send_weixin_direct
+        if not check_weixin_requirements():
+            return {"error": "Weixin requirements not met. Need aiohttp + cryptography."}
+    except ImportError:
+        return {"error": "Weixin adapter not available."}
+
+    try:
+        return await send_weixin_direct(
+            extra=pconfig.extra,
+            token=pconfig.token,
+            chat_id=chat_id,
+            message=message,
+            media_files=media_files,
+        )
+    except Exception as e:
+        return _error(f"Weixin send failed: {e}")
+
+
 async def _send_bluebubbles(extra, chat_id, message):
     """Send via BlueBubbles iMessage server using the adapter's REST API."""
     try: