feat(editor): support preview mode in code block (#11805)

<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit

- **New Features**
  - Introduced a preview mode for code blocks, allowing users to toggle between code and rendered previews (e.g., HTML output) directly within the editor.
  - Added a preview toggle button to the code block toolbar for supported languages.
  - Enabled dynamic rendering of code block previews using a shared WebContainer, allowing live HTML previews in an embedded iframe.
  - Added HTML preview support with loading and error states for enhanced user feedback.
  - Integrated the preview feature as a view extension provider for seamless framework support.

- **Bug Fixes**
  - Improved toolbar layout and button alignment for a cleaner user interface.

- **Tests**
  - Added end-to-end tests to verify the new code block preview functionality and language switching behavior.

- **Chores**
  - Updated development server configuration to include enhanced security headers.
  - Added a new runtime dependency for WebContainer support.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

blocksuite/affine/blocks/code/src/code-toolbar/config.ts

@@ -42,6 +42,18 @@ export const PRIMARY_GROUPS: MenuItemGroup<CodeBlockToolbarContext>[] = [
           };
         },
       },
+      {
+        type: 'preview',
+        generate: ({ blockComponent }) => {
+          return {
+            action: noop,
+            render: () => html`
+              <preview-button .blockComponent=${blockComponent}>
+              </preview-button>
+            `,
+          };
+        },
+      },
       {
         type: 'copy-code',
         label: 'Copy code',