fix: webhook platform support — skip home channel prompt, disable tool progress (salvage #4363)

Cherry-picked from PR #4363 by @bennyhodl with follow-up fixes:

- Skip 'No home channel' prompt for webhook platform (webhooks deliver
  to configured targets, not a home channel)
- Disable tool progress for webhooks (no message editing support)
- Add webhook to PLATFORMS in tools_config.py and skills_config.py
- Add hermes-webhook toolset to toolsets.py + hermes-gateway includes
- Removed overly aggressive <50 char content filter that blocked
  legitimate short responses (tool progress already handled at source)

Co-authored-by: bennyhodl <bennyhodl@users.noreply.github.com>

hermes_cli/tools_config.py

@@ -150,6 +150,7 @@ PLATFORMS = {
     "wecom": {"label": "💬 WeCom", "default_toolset": "hermes-wecom"},
     "api_server": {"label": "🌐 API Server", "default_toolset": "hermes-api-server"},
     "mattermost": {"label": "💬 Mattermost", "default_toolset": "hermes-mattermost"},
+    "webhook": {"label": "🔗 Webhook", "default_toolset": "hermes-webhook"},
 }