[docs] Update documentation for unassign-from-user safe output

docs/src/content/docs/reference/safe-outputs.md

@@ -52,6 +52,7 @@ The agent requests issue creation; a separate job with `issues: write` creates i
 - [**Assign Milestone**](#assign-milestone-assign-milestone) (`assign-milestone`) - Assign issues to milestones (max: 1)
 - [**Assign to Agent**](#assign-to-agent-assign-to-agent) (`assign-to-agent`) - Assign Copilot agents to issues or PRs (max: 1)
 - [**Assign to User**](#assign-to-user-assign-to-user) (`assign-to-user`) - Assign users to issues (max: 1)
+- [**Unassign from User**](#unassign-from-user-unassign-from-user) (`unassign-from-user`) - Remove user assignments from issues or PRs (max: 1)
 
 ### Projects, Releases & Assets
 
@@ -1279,6 +1280,19 @@ safe-outputs:
     target-repo: "owner/repo"  # cross-repository
 ```
 
+### Unassign from User (`unassign-from-user:`)
+
+Removes user assignments from issues or pull requests. Restrict with `allowed` list to control which users can be unassigned. Target: `"triggering"` (issue/PR event), `"*"` (any), or number.
+
+```yaml wrap
+safe-outputs:
+  unassign-from-user:
+    allowed: [user1, user2]    # restrict to specific users
+    max: 1                     # max unassignments (default: 1)
+    target: "*"                # "triggering" (default), "*", or number
+    target-repo: "owner/repo"  # cross-repository
+```
+
 ## Cross-Repository Operations
 
 Many safe outputs support `target-repo`. Requires PAT (`github-token` or `GH_AW_GITHUB_TOKEN`)-default `GITHUB_TOKEN` is current-repo only. Use specific names (no wildcards).