fix: complete Weixin platform parity audit — 16 missing integration points

Systematic audit found Weixin missing from:

Code:
- gateway/run.py: early WEIXIN_ALLOW_ALL_USERS env check
- gateway/platforms/webhook.py: cross-platform delivery routing
- hermes_cli/dump.py: platform detection for config export
- hermes_cli/setup.py: hermes setup wizard platform list + _setup_weixin
- hermes_cli/skills_config.py: platform labels for skills config UI

Docs (11 pages):
- developer-guide/architecture.md: platform adapter listing
- developer-guide/cron-internals.md: delivery target table
- developer-guide/gateway-internals.md: file tree
- guides/cron-troubleshooting.md: supported platforms list
- integrations/index.md: platform links
- reference/toolsets-reference.md: toolset table
- user-guide/configuration.md: platform keys for tool_progress
- user-guide/features/cron.md: delivery target table
- user-guide/messaging/index.md: intro text, feature table,
  mermaid diagram, toolset table, setup links
- user-guide/messaging/webhooks.md: deliver field + routing table
- user-guide/sessions.md: platform identifiers table

website/docs/user-guide/messaging/index.md

@@ -6,7 +6,7 @@ description: "Chat with Hermes from Telegram, Discord, Slack, WhatsApp, Signal,
 
 # Messaging Gateway
 
-Chat with Hermes from Telegram, Discord, Slack, WhatsApp, Signal, SMS, Email, Home Assistant, Mattermost, Matrix, DingTalk, Feishu/Lark, WeCom, BlueBubbles (iMessage), or your browser. The gateway is a single background process that connects to all your configured platforms, handles sessions, runs cron jobs, and delivers voice messages.
+Chat with Hermes from Telegram, Discord, Slack, WhatsApp, Signal, SMS, Email, Home Assistant, Mattermost, Matrix, DingTalk, Feishu/Lark, WeCom, Weixin, BlueBubbles (iMessage), or your browser. The gateway is a single background process that connects to all your configured platforms, handles sessions, runs cron jobs, and delivers voice messages.
 
 For the full voice feature set — including CLI microphone mode, spoken replies in messaging, and Discord voice-channel conversations — see [Voice Mode](/docs/user-guide/features/voice-mode) and [Use Voice Mode with Hermes](/docs/guides/use-voice-mode-with-hermes).
 
@@ -27,6 +27,7 @@ For the full voice feature set — including CLI microphone mode, spoken replies
 | DingTalk | — | — | — | — | — | ✅ | ✅ |
 | Feishu/Lark | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ |
 | WeCom | ✅ | ✅ | ✅ | — | — | ✅ | ✅ |
+| Weixin | ✅ | ✅ | ✅ | — | — | ✅ | ✅ |
 | BlueBubbles | — | ✅ | ✅ | — | ✅ | ✅ | — |
 
 **Voice** = TTS audio replies and/or voice message transcription. **Images** = send/receive images. **Files** = send/receive file attachments. **Threads** = threaded conversations. **Reactions** = emoji reactions on messages. **Typing** = typing indicator while processing. **Streaming** = progressive message updates via editing.
@@ -50,6 +51,7 @@ flowchart TB
             dt[DingTalk]
     fs[Feishu/Lark]
     wc[WeCom]
+    wx[Weixin]
     bb[BlueBubbles]
             api["API Server<br/>(OpenAI-compatible)"]
             wh[Webhooks]
@@ -71,6 +73,10 @@ flowchart TB
     mm --> store
     mx --> store
     dt --> store
+    fs --> store
+    wc --> store
+    wx --> store
+    bb --> store
     api --> store
     wh --> store
     store --> agent
@@ -354,6 +360,7 @@ Each platform has its own toolset:
 | DingTalk | `hermes-dingtalk` | Full tools including terminal |
 | Feishu/Lark | `hermes-feishu` | Full tools including terminal |
 | WeCom | `hermes-wecom` | Full tools including terminal |
+| Weixin | `hermes-weixin` | Full tools including terminal |
 | BlueBubbles | `hermes-bluebubbles` | Full tools including terminal |
 | API Server | `hermes` (default) | Full tools including terminal |
 | Webhooks | `hermes-webhook` | Full tools including terminal |
@@ -373,6 +380,7 @@ Each platform has its own toolset:
 - [DingTalk Setup](dingtalk.md)
 - [Feishu/Lark Setup](feishu.md)
 - [WeCom Setup](wecom.md)
+- [Weixin Setup (WeChat)](weixin.md)
 - [BlueBubbles Setup (iMessage)](bluebubbles.md)
 - [Open WebUI + API Server](open-webui.md)
 - [Webhooks](webhooks.md)