feat(gateway): add all missing platforms to interactive setup wizard

Wire Signal, Email, SMS (Twilio), DingTalk, Feishu/Lark, and WeCom into
the hermes setup gateway interactive wizard. These platforms all had
working adapters and _PLATFORMS entries in gateway.py but were invisible
in the setup checklist — users had to manually edit .env to configure them.

Changes:
- gateway.py: Add _setup_email/sms/dingtalk/feishu/wecom functions
  delegating to _setup_standard_platform (Signal already had a custom one)
- setup.py: Add wrapper functions for all 6 new platforms
- setup.py: Add all 6 to _GATEWAY_PLATFORMS checklist registry
- setup.py: Add missing env vars to any_messaging check
- setup.py: Add all missing platforms to _get_section_config_summary
  (was also missing Matrix, Mattermost, Weixin, Webhooks)
- docs: Add FEISHU_ALLOWED_USERS and WECOM_ALLOWED_USERS examples

Incorporates and extends the work from PR #7918 by bugmaker2.

hermes_cli/gateway.py

@@ -1981,6 +1981,36 @@ def _setup_whatsapp():
     cmd_whatsapp(argparse.Namespace())
 
 
+def _setup_email():
+    """Configure Email via the standard platform setup."""
+    email_platform = next(p for p in _PLATFORMS if p["key"] == "email")
+    _setup_standard_platform(email_platform)
+
+
+def _setup_sms():
+    """Configure SMS (Twilio) via the standard platform setup."""
+    sms_platform = next(p for p in _PLATFORMS if p["key"] == "sms")
+    _setup_standard_platform(sms_platform)
+
+
+def _setup_dingtalk():
+    """Configure DingTalk via the standard platform setup."""
+    dingtalk_platform = next(p for p in _PLATFORMS if p["key"] == "dingtalk")
+    _setup_standard_platform(dingtalk_platform)
+
+
+def _setup_feishu():
+    """Configure Feishu / Lark via the standard platform setup."""
+    feishu_platform = next(p for p in _PLATFORMS if p["key"] == "feishu")
+    _setup_standard_platform(feishu_platform)
+
+
+def _setup_wecom():
+    """Configure WeCom (Enterprise WeChat) via the standard platform setup."""
+    wecom_platform = next(p for p in _PLATFORMS if p["key"] == "wecom")
+    _setup_standard_platform(wecom_platform)
+
+
 def _is_service_installed() -> bool:
     """Check if the gateway is installed as a system service."""
     if supports_systemd_services():