feat: enable Prism syntax highlighting in code blocks

- Register CodeHighlightNode in the editor node set
- Add CodeHighlightPlugin that calls registerCodeHighlighting
- Map 20+ Prism token types to mc-tok-* CSS classes with dark theme colors
- Explicitly import prismjs + language components and set globalThis.Prism
  before @lexical/code-prism loads, fixing a Vite dev-mode race where
  the CJS shim could initialize the tokenizer before the global was set
- Added @types/prismjs for type checking

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

bun.lock

@@ -25,6 +25,7 @@
         "@lexical/headless": "0.42.0",
         "@tailwindcss/vite": "^4.2.2",
         "@types/node": "^25.5.0",
+        "@types/prismjs": "^1.26.6",
         "@types/react": "^19.2.14",
         "@types/react-dom": "^19.2.3",
         "@vitejs/plugin-react": "5.1.0",
@@ -338,6 +339,8 @@
 
     "@types/node": ["@types/node@25.5.0", "", { "dependencies": { "undici-types": "~7.18.0" } }, "sha512-jp2P3tQMSxWugkCUKLRPVUpGaL5MVFwF8RDuSRztfwgN1wmqJeMSbKlnEtQqU8UrhTmzEmZdu2I6v2dpp7XIxw=="],
 
+    "@types/prismjs": ["@types/prismjs@1.26.6", "", {}, "sha512-vqlvI7qlMvcCBbVe0AKAb4f97//Hy0EBTaiW8AalRnG/xAN5zOiWWyrNqNXeq8+KAuvRewjCVY1+IPxk4RdNYw=="],
+
     "@types/react": ["@types/react@19.2.14", "", { "dependencies": { "csstype": "^3.2.2" } }, "sha512-ilcTH/UniCkMdtexkoCN0bI7pMcJDvmQFPvuPvmEaYA/NSfFTAgdUSLAoVjaRJm7+6PvcM+q1zYOwS4wTYMF9w=="],
 
     "@types/react-dom": ["@types/react-dom@19.2.3", "", { "peerDependencies": { "@types/react": "^19.2.0" } }, "sha512-jp2L/eY6fn+KgVVQAOqYItbF0VY/YApe5Mz2F0aykSO8gx31bYCZyvSeYxCHKvzHG5eZjc+zyaS5BrBWya2+kQ=="],