Why

The TUI currently exposes overlapping command names for the same permissions flow: /permissions and the older /approvals alias. It also uses /autoreview for the manual retry flow, even though the action users take there is approving one denied auto-review request.

This change makes the command surface consistent with the hard rebrand:

• /permissions is the only command for permission settings.
• /approve is the command for approving a recent auto-review denial.

What changed

• Removed the legacy /approvals slash command and its dispatch path.
• Kept /permissions as the single permissions command shown and accepted by the TUI.
• Renamed the auto-review denial command from /autoreview to /approve.
• Updated nearby comments so they refer to /permissions rather than the retired /approvals name.

Verification

• Updated the slash-command unit test to assert that AutoReview now renders and parses as approve.