fix(ribbon): light the button for prefixed commands too; drop PR screenshots

_LINE / .LINE reached show_command with the prefix and matched nothing;
strip it the way the Start-tab gate already does. The before/after
screenshots only illustrate the PR and stay on its branch.

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

src/app/commands/mod.rs

@@ -230,7 +230,8 @@ impl OpenCADStudio {
         // started (typed, alias, shortcut, Repeat), so the user sees where it
         // lives. A transparent command returned above and leaves the running
         // command's highlight alone.
-        self.ribbon.show_command(cmd);
+        self.ribbon
+            .show_command(strip_command_prefixes(cmd).unwrap_or(cmd));
 
         if !self.suppress_plugin_dispatch && crate::plugin::try_dispatch(self, i, cmd) {
             // try_dispatch returns true for both finished commands and interactive