When a tirith content-security warning is present the approval backend
forces allow_permanent=False and silently downgrades an "always" choice to
session scope (the persistence loop in check_all_command_guards only honors
"always" → permanent when no tirith finding exists). But the gateway notify
payload that drives the TUI and the Electron desktop app never carried that
flag, so both surfaces always rendered "Always allow" — offering a permanent
allow the backend would quietly refuse to persist.

Plumb allow_permanent end-to-end:
- tools/approval.py: include `allow_permanent: not has_tirith` in the gateway
  approval_data the notify callback emits as `approval.request`.
- ui-tui: thread `allowPermanent` through the event handler, gateway types,
  and ApprovalReq; ApprovalPrompt drops the "always" option (and renumbers the
  quick-pick keys) when it's false.
- apps/desktop: thread `allow_permanent` through the gateway payload type, the
  per-session approval store, and the inline ApprovalBar, which now hides the
  "Always allow…" dropdown item when permanent allow is disallowed — reusing
  the existing DropdownMenu / confirm-Dialog UI.

The desktop/TUI render path for approvals already landed in NousResearch#38578 (the root
cause of approvals not surfacing in the GUI); this completes the salvage of
NousResearch#37856 by carrying allow_permanent across both surfaces. NousResearch#37856's original
thread-local _block() approach is dropped: desktop/TUI approvals resolve via
approval.respond → resolve_gateway_approval (the per-session queue), not the
_block()/request_id correlation, so a worker-thread callback waiting on _block
would never be released by the real UI.

Tests: gateway notify payload carries allow_permanent (True without tirith,
False with a tirith warning); ui-tui approvalAction reduced option set +
event-handler allowPermanent propagation; desktop store round-trip + the
ApprovalBar showing/hiding "Always allow".

Supersedes NousResearch#37856
Closes NousResearch#37812

Co-authored-by: LeonSGP43 <cine.dreamer.one@gmail.com>