Docs(chore[dev]): Set Astro dev port to 4350

why: Avoid clashing with the default Astro dev port.
what:
- Configure the docs site server port in astro.config.ts

Author: tony

astro/packages/site/docs/astro.config.ts

@@ -6,6 +6,9 @@ import { defineConfig } from 'astro/config'
 export default defineConfig({
   site: 'https://libtmux.git-pull.com',
   integrations: [react(), mdx()],
+  server: {
+    port: 4350,
+  },
   vite: {
     plugins: [tailwind()],
   },