fix(commands): strip _/. name prefixes only when the name as written is unknown

#1584 stripped the prefixes before dispatch, which turned the ribbon's own
internal names (_PCCROPPOLY, _XREFEDIT, _PDFULSNAP, ...) into unknown
commands. A name is now tried as written and retried without its prefixes
only when no family handles it; the Start-tab gate judges the bare name.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/app/command_driver/utilities.rs

@@ -1197,4 +1197,3 @@ impl OpenCADStudio {
         self.run_command_line(trimmed)
     }
 }
-

src/app/commands/fileops.rs

@@ -489,7 +489,7 @@ mod tests {
     }
 
     #[test]
-    fn autodesk_command_prefixes_strip_underscore_and_dot() {
+    fn command_name_prefixes_are_stripped() {
         let mut app = fresh_app();
         let i = app.active_tab;
         let before_count = app.tabs[i].scene.document.entities().count();
@@ -535,4 +535,3 @@ ZOOM EXTENTS
         assert_eq!(app.tabs[i].scene.document.entities().count(), 8);
     }
 }
-

src/app/commands/mod.rs

@@ -116,11 +116,6 @@ impl OpenCADStudio {
             Some(rest) => (rest.trim(), true),
             None => (cmd, false),
         };
-        let cmd = cmd.trim();
-        // AutoCAD command prefixes: '_' (international name), '.' (built-in name bypass)
-        let cmd = cmd.strip_prefix('.').unwrap_or(cmd);
-        let cmd = cmd.strip_prefix('_').unwrap_or(cmd);
-        let cmd = cmd.strip_prefix('.').unwrap_or(cmd);
         let resolved = self.resolve_alias(cmd);
         let cmd = resolved.as_deref().unwrap_or(cmd);
         if is_spacemouse_command(cmd) {
@@ -201,7 +196,7 @@ impl OpenCADStudio {
         // editors (shortcuts, aliases) — none of them read the scene. This is
         // the single place that decides; `on_ribbon_tool_click` defers to it
         // rather than keeping a second, blunter copy (#388, #389).
-        if self.tabs[i].is_start && !start_allowed(cmd) {
+        if self.tabs[i].is_start && !start_allowed(strip_command_prefixes(cmd).unwrap_or(cmd)) {
             self.command_line
                 .push_info(crate::t!("No drawing open. Use NEW or OPEN to start a drawing.").as_ref());
             return Task::none();
@@ -233,6 +228,15 @@ impl OpenCADStudio {
             return t;
         }
 
+        // Scripts and typed input may carry the international (`_`) and
+        // built-in (`.`) name prefixes (`_LINE`, `._LINE`). Ribbon tools
+        // dispatch internal names that start with `_` themselves
+        // (`_PCCROPPOLY`), so a name is tried as written first and loses its
+        // prefixes only when nothing handles it.
+        if let Some(bare) = strip_command_prefixes(cmd) {
+            return self.dispatch_command_inner(bare, allow_suggest);
+        }
+
         // No family matched. From the interactive command line, run the
         // closest autocomplete suggestion instead of erroring, so a partial
         // command completes on Enter (`BAC` → `BACKGROUND`). The verb's own
@@ -1036,3 +1040,10 @@ mod marquee_cancel_tests {
         );
     }
 }
+
+/// `cmd` without its leading `_` / `.` name prefixes (`_LINE`, `.LINE`,
+/// `._LINE`), or `None` when it carries none.
+fn strip_command_prefixes(cmd: &str) -> Option<&str> {
+    let bare = cmd.trim_start_matches(['_', '.']);
+    (bare.len() != cmd.len() && !bare.is_empty()).then_some(bare)
+}