tlc: add Edit extension/menu/highlighting file commands

Wire three Command menu items that open TLC's config files in
the built-in editor: extensions, user menu, and file highlighting
rules. Files are created empty if they don't exist.

Cmd::EditExtensionFile → ~/.config/tlc/extensions
Cmd::EditMenuFile → ~/.config/tlc/menu
Cmd::EditHighlightFile → ~/.config/tlc/filehighlight.ini

Added open_config_file() helper in dialog_ops.rs that resolves
the config dir via ProjectDirs, creates parent + empty file if
missing, then opens the editor.

Command menu now has all 20 items (was 17/20).

local/recipes/tui/tlc/PLAN.md

@@ -790,9 +790,9 @@ MC's F9 bar has 5 entries: **Left** · **File** · **Command** · **Options** ·
 | 15 | Screen list | Alt-` | ✅ Done | — | `Cmd::ScreenList` dialog (15g) |
 | 16 | Undelete files | (none) | ❌ N/A | SKIP |
 | 17 | Listing format edit | (none) | ❌ Missing | SKIP |
-| 18 | Edit extension file | (menu) | ❌ Missing | LOW |
-| 19 | Edit menu file | (menu) | ❌ Missing | LOW |
-| 20 | Edit highlighting file | (menu) | ❌ Missing | LOW |
+| 18 | Edit extension file | (menu) | ✅ Done | — | Opens `~/.config/tlc/extensions` in editor |
+| 19 | Edit menu file | (menu) | ✅ Done | — | Opens `~/.config/tlc/menu` in editor |
+| 20 | Edit highlighting file | (menu) | ✅ Done | — | Opens `~/.config/tlc/filehighlight.ini` in editor |
 
 #### Options Menu (10 items)
 

local/recipes/tui/tlc/source/src/filemanager/dialog_ops.rs

@@ -268,6 +268,32 @@ impl FileManager {
         self.status.set_message(format!("Editing {}:{}", path.display(), line));
     }
 
+    /// Open `~/.config/tlc/<name>` in the editor, creating it
+    /// empty if it does not exist. Used by the Command menu's
+    /// "Edit extension file", "Edit menu file", and "Edit
+    /// highlighting file" entries.
+    pub fn open_config_file(&mut self, name: &str) {
+        let path = match directories::ProjectDirs::from("org", "redbearos", "tlc") {
+            Some(d) => d.config_dir().join(name),
+            None => {
+                self.status
+                    .set_message("Cannot determine config directory".to_string());
+                return;
+            }
+        };
+        if !path.exists() {
+            if let Some(parent) = path.parent() {
+                let _ = std::fs::create_dir_all(parent);
+            }
+            let _ = std::fs::write(&path, "");
+        }
+        let mut ed = crate::editor::Editor::open(&path);
+        let _ = ed.restore_cursor_position();
+        self.editor = Some(ed);
+        self.status
+            .set_message(format!("Editing {}", path.display()));
+    }
+
     /// Open the F3 viewer at a specific 1-based line number.
     pub fn open_viewer_at_line(&mut self, path: &Path, line: u64) {
         match crate::viewer::Viewer::open(path) {

local/recipes/tui/tlc/source/src/filemanager/dispatch.rs

@@ -516,6 +516,18 @@ impl FileManager {
                 )));
                 Ok(true)
             }
+            Cmd::EditExtensionFile => {
+                self.open_config_file("extensions");
+                Ok(true)
+            }
+            Cmd::EditMenuFile => {
+                self.open_config_file("menu");
+                Ok(true)
+            }
+            Cmd::EditHighlightFile => {
+                self.open_config_file("filehighlight.ini");
+                Ok(true)
+            }
         }
     }
 

local/recipes/tui/tlc/source/src/filemanager/menubar.rs

@@ -117,6 +117,10 @@ fn build_menus() -> Vec<Menu> {
             MenuItem::item("Active VFS list", Cmd::VfsList),
             MenuItem::item("Background jobs", Cmd::Jobs),
             MenuItem::separator(),
+            MenuItem::item("Edit extension file", Cmd::EditExtensionFile),
+            MenuItem::item("Edit menu file", Cmd::EditMenuFile),
+            MenuItem::item("Edit highlighting file", Cmd::EditHighlightFile),
+            MenuItem::separator(),
             MenuItem::item("Toggle panels", Cmd::TogglePanels),
         ]),
         Menu::new("Options", vec![

local/recipes/tui/tlc/source/src/keymap/mod.rs

@@ -183,6 +183,12 @@ pub enum Cmd {
     Encoding,
     /// Alt-n — open a network connection (FTP/SFTP/Shell).
     Connection,
+    /// Command menu — edit the extension mapping file.
+    EditExtensionFile,
+    /// Command menu — edit the user menu file.
+    EditMenuFile,
+    /// Command menu — edit the file highlighting rules.
+    EditHighlightFile,
 }
 
 impl Cmd {
@@ -265,6 +271,9 @@ impl Cmd {
             Cmd::PanelFilter => "Panel filter",
             Cmd::Encoding => "Display encoding",
             Cmd::Connection => "Network connection",
+            Cmd::EditExtensionFile => "Edit extension file",
+            Cmd::EditMenuFile => "Edit menu file",
+            Cmd::EditHighlightFile => "Edit highlighting file",
         }
     }
 }