Upgrade VitePress to 2.0.0-alpha.15

- Update vitepress from 1.5.0 to 2.0.0-alpha.15
- Update @shikijs/vitepress-twoslash from 3.7.0 to 3.20.0
- Add markdown.languages config for Shiki v3 lazy loading compatibility

VitePress 2.0 uses lazy loading for Shiki languages, requiring explicit
language declarations when using transformers like twoslash.

Co-Authored-By: Claude <[email protected]>

Author: dahlia

docs/.vitepress/config.mts

@@ -168,6 +168,7 @@ export default defineConfig({
   ignoreDeadLinks: true,
 
   markdown: {
+    languages: ["js", "jsx", "ts", "tsx", "typescript", "bash", "sh", "shell", "json", "text", "html"],
     codeTransformers: [
       transformerTwoslash({
         twoslashOptions: {

docs/package.json

@@ -7,7 +7,7 @@
     "@fedify/redis": "^1.8.7",
     "@fedify/sqlite": "^1.8.7",
     "@js-temporal/polyfill": "catalog:",
-    "@shikijs/vitepress-twoslash": "^3.7.0",
+    "@shikijs/vitepress-twoslash": "^3.20.0",
     "@types/deno": "^2.3.0",
     "@types/node": "^24.0.3",
     "ioredis": "^5.6.1",
@@ -17,7 +17,7 @@
     "postgres": "^3.4.7",
     "srvx": "^0.8.0",
     "typescript": "^5.8.3",
-    "vitepress": "^1.5.0",
+    "vitepress": "^2.0.0-alpha.15",
     "vitepress-plugin-group-icons": "^1.3.3",
     "vitepress-plugin-llms": "^1.1.0"
   },