feat(registry): add code snippet blocks with VS Code workbench (#1113)

* feat(registry): add VS Code theme visualizer example

Full VS Code workbench recreation with per-character typing animation
across 12 built-in themes. Includes activity bar, sidebar, tabs,
editor with line-by-line cursor tracking, terminal panel, and status
bar — all driven by official VS Code theme JSON files.

Themes: Dark Modern, Dark 2026, Dark+, Light Modern, Light 2026,
Light+, Visual Studio Dark, Visual Studio Light, High Contrast,
High Contrast Light, Solarized Light, Monokai.

Includes build scripts to regenerate compositions from theme JSON.

* feat(registry): add 12 code snippet blocks for hyperframes add code

Individual blocks for each VS Code built-in theme, all tagged "code"
so `npx hyperframes add code` installs the full set.

Each block is a self-contained VS Code workbench with per-character
typing animation, activity bar, sidebar, tabs, terminal, and status
bar driven by official theme JSON data.

* docs: add mdx pages for code snippet blocks and example

- 12 block doc pages under catalog/blocks/code-snippet-*
- "Code Snippets" nav group in docs.json
- vscode-theme-visualizer entry in examples.mdx

* docs: revert examples.mdx — code snippets belong in catalog only

* docs: drop redundant 'Code Snippet' prefix from sidebar titles

* docs: add video previews to code snippet catalog pages

* style: format HTML, CSS, and MJS files for CI

* fix: address review feedback — build pipeline, LICENSE, dead code, nav order

1. Build script now regenerates both example compositions AND published
   blocks in registry/blocks/code-snippet-*/, keeping them in sync.
2. Add MIT LICENSE for vendored VS Code theme JSONs (microsoft/vscode).
3. Remove dead `chars` variable from runtime, build script, all blocks,
   and all example compositions.
4. Alphabetize Code Snippets nav group in docs.json to match catalog
   convention.

* style: format all build-generated files (render-entries, CSS, index)

docs/catalog/blocks/code-snippet-dark-2026.mdx

@@ -0,0 +1,67 @@
+---
+title: "Dark 2026"
+description: "The newest VS Code dark theme with refined token scopes and updated palette."
+---
+
+# Dark 2026
+
+VS Code workbench with per-character typing animation in the Dark 2026 theme. Full editor chrome with activity bar, sidebar, tabs, terminal, and status bar.
+
+`code` `developer` `showcase` `vscode`
+
+<video className="w-full aspect-video rounded-xl object-cover bg-zinc-100 dark:bg-zinc-800" src="https://static.heygen.ai/hyperframes-oss/docs/images/catalog/blocks/code-snippet-dark-2026.mp4" poster="https://static.heygen.ai/hyperframes-oss/docs/images/catalog/blocks/code-snippet-dark-2026.png" autoPlay muted loop playsInline />
+
+## Install
+
+<CodeGroup>
+
+```bash Terminal
+npx hyperframes add code-snippet-dark-2026
+```
+
+</CodeGroup>
+
+Install all code snippet themes at once:
+
+```bash Terminal
+npx hyperframes add code
+```
+
+## Details
+
+| Property | Value |
+| --- | --- |
+| Type | Block |
+| Dimensions | 1920×1080 |
+| Duration | 11s |
+
+## Files
+
+| File | Target | Type |
+| --- | --- | --- |
+| `code-snippet-dark-2026.html` | `compositions/code-snippet-dark-2026.html` | hyperframes:composition |
+| `background.jpeg` | `assets/background.jpeg` | hyperframes:asset |
+
+## Usage
+
+After installing, add the block to your host composition:
+
+```html
+<div
+  data-composition-id="code-snippet-dark-2026"
+  data-composition-src="compositions/code-snippet-dark-2026.html"
+  data-start="0"
+  data-duration="11"
+  data-track-index="1"
+  data-width="1920"
+  data-height="1080"
+></div>
+```
+
+## Features
+
+- Full VS Code workbench recreation — activity bar, sidebar, explorer tree, editor tabs, breadcrumbs, terminal panel, status bar
+- Per-character typing animation with cursor tracking and active line highlight
+- Colors sourced from official `microsoft/vscode` built-in theme JSON
+- 3D perspective tilt at the end of the typing sequence
+- Terminal panel with mock test output