feat(codemirror): add Vim :w evaluate, :q stop, and gc/gcc toggle comment via custom events; docs: add Vim shortcuts page and link from REPL manual

website/src/pages/technical-manual/repl.mdx

@@ -117,6 +117,10 @@ Here's an example AST for `c3 [e3 g3]`
 
 which translates to `seq(c3, seq(e3, g3))`
 
+## Vim Keybindings
+
+See the separate page on Vim shortcuts for a quick reference: [/technical-manual/vim](/technical-manual/vim)
+
 ## Scheduling Events
 
 After an instance of `Pattern` is obtained from the user code,

website/src/pages/technical-manual/vim.mdx

@@ -0,0 +1,36 @@
+---
+title: Vim Shortcuts
+layout: ../../layouts/MainLayout.astro
+---
+
+# Vim Shortcuts in the REPL
+
+When the REPL editor (CodeMirror) is configured to use Vim keybindings, the following commands are available:
+
+- :w — Evaluate the current code
+  - Triggers the same evaluation as Ctrl+Enter / Alt+Enter
+  - You’ll see messages in the Console panel such as:
+    - [vim] :w — evaluating code
+    - [repl] evaluate via event
+    - [eval] code updated
+
+- :q — Stop/pause playback
+  - Triggers the same stop action as Alt+.
+  - Useful to quickly stop scheduling without leaving Vim mode
+
+- gc — Toggle line comments for the current selection(s)
+  - Works in normal and visual mode
+  - If there’s a selection, all selected lines are toggled
+
+- gcc — Toggle comment for the current line (normal mode)
+
+Notes
+
+- Behavior respects the current language mode in the editor for comment syntax.
+- If multiple REPL editors are open, commands target the active editor. The implementation dispatches custom events handled by the editor.
+- If you don’t see the Console panel, open the right panel in the REPL UI.
+
+Troubleshooting
+
+- If :w logs but evaluation doesn’t apply, ensure Vim keybindings are active and try again. You can also use Ctrl+Enter as a fallback.
+- For :q / gc / gcc, ensure focus is inside the editor. If an error occurs, reload the page to reset editor state and try again.