fix(settings): disable the unimplemented Tor option and tell its users

The "Use Tor" checkbox was saved but never read: no build routed any
traffic (node, RPC, price/update/bootstrap/pool HTTP or Lite gRPC)
through Tor, so users who ticked it believed they were anonymous.

- The checkbox is disabled and always shown unticked, on the Settings
  page and in the legacy Settings window. Its tooltip says it is not
  available and gives the alternatives: for the node, proxy=127.0.0.1:9050
  in DRAGONX.conf with Tor running; otherwise a system-wide VPN/Tor (Lite
  builds get the short version). The "Use Tor" label is kept.
- Behaviour change: a stored use_tor=true is cleared once at startup
  (Settings::consumeLegacyUseTor + a synchronous save before the async
  writer and any Settings page state), with a 20 s warning in the user's
  language. The cleared key is the "already told" flag, so the notice
  never repeats. No settings format change.
- 3 new strings (tt_tor_unavailable, tt_tor_unavailable_lite,
  tor_never_applied_notice) in all 8 languages; the tooltip wraps at
  tor-tooltip-wrap-width from ui.toml.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

res/themes/ui.toml

@@ -1352,6 +1352,8 @@ rpc-label-width = { size = 85.0 }
 security-combo-width = { size = 120.0 }
 # Wrap width of the Security band's "PIN out of date" tooltip (a long sentence in every language).
 pin-tooltip-wrap-width = { size = 420.0 }
+# Wrap width of the disabled "Use Tor" checkbox's tooltip (Settings page and the legacy Settings window).
+tor-tooltip-wrap-width = { size = 420.0 }
 node-grid-breakpoint = { size = 900.0 }
 port-input-min-width = { size = 60.0 }
 port-input-width-ratio = { size = 0.4 }