docs: MCP + cron + plugin lifecycle plus channel env-block cross-links

docs/channels/irc.md

@@ -237,6 +237,14 @@ Default account supports:
 - `IRC_NICKSERV_PASSWORD`
 - `IRC_NICKSERV_REGISTER_EMAIL`
 
+<Note>
+`IRC_HOST` is on the endpoint-block list and cannot be set from a workspace
+`.env` file. It must come from shell environment or the gateway process
+environment so that untrusted workspaces cannot redirect IRC traffic to a
+different server. See [Workspace `.env` files](/gateway/security) for the full
+list.
+</Note>
+
 ## Troubleshooting
 
 - If the bot connects but never replies in channels, verify `channels.irc.groups` **and** whether mention-gating is dropping messages (`missing-mention`). If you want it to reply without pings, set `requireMention:false` for the channel.

docs/channels/matrix.md

@@ -179,6 +179,14 @@ For example, `-` becomes `_X2D_`, so `ops-prod` maps to `MATRIX_OPS_X2D_PROD_*`.
 
 The interactive wizard only offers the env-var shortcut when those auth env vars are already present and the selected account does not already have Matrix auth saved in config.
 
+<Note>
+`MATRIX_HOMESERVER` is on the endpoint-block list and cannot be set from a
+workspace `.env` file. It must come from shell environment or the gateway
+process environment so that untrusted workspaces cannot redirect Matrix
+traffic to a different homeserver. See
+[Workspace `.env` files](/gateway/security) for the full list.
+</Note>
+
 ## Configuration example
 
 This is a practical baseline config with DM pairing, room allowlist, and E2EE enabled:

docs/channels/mattermost.md

@@ -109,6 +109,14 @@ Set these on the gateway host if you prefer env vars:
 
 Env vars apply only to the **default** account (`default`). Other accounts must use config values.
 
+<Note>
+`MATTERMOST_URL` is on the endpoint-block list and cannot be set from a
+workspace `.env` file. It must come from shell environment or the gateway
+process environment so that untrusted workspaces cannot redirect Mattermost
+traffic to a different server. See
+[Workspace `.env` files](/gateway/security) for the full list.
+</Note>
+
 ## Chat modes
 
 Mattermost responds to DMs automatically. Channel behavior is controlled by `chatmode`:

docs/channels/synology-chat.md

@@ -89,6 +89,14 @@ For the default account, you can use env vars:
 
 Config values override env vars.
 
+<Note>
+`SYNOLOGY_CHAT_INCOMING_URL` is on the endpoint-block list and cannot be set
+from a workspace `.env` file. It must come from shell environment or the
+gateway process environment so that untrusted workspaces cannot redirect
+Synology Chat traffic to a different webhook. See
+[Workspace `.env` files](/gateway/security) for the full list.
+</Note>
+
 ## DM policy and access control
 
 - `dmPolicy: "allowlist"` is the recommended default.