React to message 4003

[1000TurquoisePogs]

Proposed changes

This PR depends upon the following PRs:
zowe/zlux-server-framework#702

One enhancement to the VT terminal UI:

1. AllowList rejection message: When the server closes the WebSocket with code 4003 (host not in allowList), the status bar now displays "Connection forbidden" instead of a generic websocket error.

Files changed:

• webClient/src/app/app.component.ts — handles WS close code 4003 in onWSError with a "Connection forbidden" message

PR Checklist

• If the changes in this PR are meant for the next release / mainline, this PR targets the "staging" branch.
• My code follows the style guidelines of this project (see: Contributing guideline)
• I have made corresponding changes to the documentation
• Relevant update to CHANGELOG.md
• My changes generate no new warnings

Testing

AllowList rejection UX:

1. Configure components.vt-ng2.allowList in zowe.yaml to exclude the target host (see zlux-server-framework PR).
2. Open the VT terminal app and attempt to connect to the excluded host.
3. Verify the status bar shows "Connection forbidden" (not a raw websocket error code or blank message).

Further comments

The 4003 close code is handled as a known application-level rejection in onWSError, parallel to how other known close codes are handled. No changes to connection logic — this is purely a UI message improvement.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud