feat: switch canonical base URL to docs.chinmina.dev

Updates the Astro site config so all builds emit canonical link tags
pointing to https://docs.chinmina.dev rather than chinmina.github.io.
Adds a vitest test asserting the site field value.

Author: jamestelfer

astro.config.mjs

@@ -67,7 +67,7 @@ const sidebar = [
 
 // https://astro.build/config
 export default defineConfig({
-  site: "https://chinmina.github.io",
+  site: "https://docs.chinmina.dev",
   trailingSlash: "never",
 
   integrations: [

astro.config.test.mjs

@@ -0,0 +1,8 @@
+import { describe, expect, it } from "vitest"
+import config from "./astro.config.mjs"
+
+describe("astro.config.mjs", () => {
+  it("sets canonical base URL to docs.chinmina.dev", () => {
+    expect(config.site).toBe("https://docs.chinmina.dev")
+  })
+})