chore: update Next.js configuration and release workflow

- Modified Next.js configuration to conditionally apply raw-loader for markdown files only on the client side.
- Increased static page generation timeout to 300 seconds for larger builds.
- Enhanced GitHub Actions release workflow by adding a step to build the Next.js frontend, ensuring the 'out' directory exists post-build.
- Simplified the beforeBuildCommand in Tauri configuration to only include the build step.

src-tauri/tauri.conf.json

@@ -7,7 +7,7 @@
     "frontendDist": "../out",
     "devUrl": "http://localhost:3000",
     "beforeDevCommand": "pnpm dev",
-    "beforeBuildCommand": "pnpm generate-changelog && pnpm build"
+    "beforeBuildCommand": "pnpm build"
   },
   "app": {
     "windows": [