feat: scaffold Astro project with en/fr i18n routing

Sets output to static (Astro default) with path-based i18n routing
(/en/, /fr/) and no unprefixed default-locale route, per the hub
landing page design spec.

tsconfig.json

@@ -0,0 +1,5 @@
+{
+  "extends": "astro/tsconfigs/strict",
+  "include": [".astro/types.d.ts", "**/*"],
+  "exclude": ["dist"]
+}