docs: bind canonical channel workspace

SKILL.md

@@ -331,3 +331,12 @@ Requires team approval for:
 ## Channel workspace standard
 
 Load `channel-workspace-organization` for channel setup, file placement, and authorized workspace migration. Canonical standard: https://gitea.lego-cloud.eu/global-skills/channel-workspace-organization . Follow that shared policy rather than duplicating it here. Existing workspace bindings below remain current until an authorized migration is completed and verified; this reference alone does not relocate files or change bindings.
+
+## Stage 2 channel workspace binding
+
+- Group: `skic-3darch`
+- Workspace: `/opt/data/channels/skic-3darch/channels/architecture`
+- Immutable source channel: `1543925248917770251`
+- Mattermost channel: `5emsqetot3rhdjc7381xa1xa6c`
+- Board: unresolved in source binding; do not use a global board
+- Preserve existing purpose folders, channel authority, and historical evidence.