Admins can now mint single-use invite links from a new section on
/settings: optional note, 1/7/30-day expiry (7 by default), and the full
/invite/{code} URL shown for handing to the invitee. Outstanding invites
(unused and unexpired) are listed so links can be re-copied without
minting duplicates. The route is gated by require_admin and the section
is hidden from non-admins.

@@ -467,3 +501,2 @@
     if user_id is None:
-        raise HTTPException(status_code=status.HTTP_410_GONE, detail="invite no longer usable")
-    return RedirectResponse("/login", status_code=status.HTTP_303_SEE_OTHER)
+        return _render_invite_unavailable(request, "expired", status.HTTP_410_GONE)

@@ -470,0 +503,4 @@
+        reason = "used" if invite is not None and invite["used_by"] is not None else "expired"
+        return _render_invite_unavailable(request, reason, status.HTTP_410_GONE)
+    request_settings: Settings = request.app.state.settings
+    session_token = new_session_token()

@@ -371,0 +470,4 @@
+        _invite_expiry(int(expires_days)),
+        cleaned_note,
+    )
+    minted_invite_url = f"{str(request.base_url).rstrip('/')}/invite/{code}"