fix(ui): clearok(stdscr) in ui_resume to clear vim screen residue

ncurses didn't know the editor clobbered the physical screen, so the
first refresh after vim exit was a no-op diff. Stale frame stayed
visible until the next keystroke triggered readline redisplay.

src/tools/editor.c

@@ -182,7 +182,7 @@ editor_emergency_kill(void)
         return;
     }
     log_warning("[Editor] aborting editor pid %d", editor_pid);
-    kill(editor_pid, SIGCONT);  // wake if STOPPED; no-op otherwise
+    kill(editor_pid, SIGCONT); // wake if STOPPED; no-op otherwise
     kill(editor_pid, SIGTERM);
     // _editor_exit_cb will restore the UI when the child reaps.
 }

src/ui/core.c

@@ -198,6 +198,7 @@ void
 ui_resume(void)
 {
     ui_suspended = FALSE;
+    clearok(stdscr, TRUE); // ncurses can't see vim's screen clobber
     refresh();
     inp_resume();
 }