feat(ui): drop echo toasts for actions the screen already shows

L1: Counters reset, Trail reset, Contact added/deleted, Logged in (admin),
Logged out, Channel deleted, Share target / Bot channel / Bot room set,
PIN set/cleared, Preset saved/deleted, and Unpinned on the favourites grid.
L2: Channel deleted, Counters reset, Region/Preset/Scope/Waypoint deleted,
Target cleared, Trail cleared, Message history deleted, Contact added/deleted.
Failures and Unpinned where the item leaves the screen stay.

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

examples/companion_radio/ui-lvgl/RadioExtras.h

@@ -99,7 +99,6 @@ void UITask::presetAction(uint8_t act) {
       prefsSave();
       navClosePopup();
       rebuildRadio();
-      showToast("Preset deleted");
       break;
   }
 }
@@ -217,7 +216,6 @@ void UITask::scopeAction(uint8_t act) {
       if (s_scope > 0) the_mesh.removeScope((uint8_t)s_scope);
       navClosePopup();
       buildScopes();
-      showToast("Scope deleted");
       break;
   }
 }