[PIE-14] More robust API proxy (!7)

Finally! Using an Astro API Route to handle all the queries which works like a dream. Also created a custom function to get the relative path for image files, fixing any external access issues.
Co-authored-by: june <self@breadone.net>
Co-committed-by: june <self@breadone.net>

src/pages/api/[...proxy].ts

@@ -0,0 +1,16 @@
+import type { APIRoute } from "astro";
+
+// THANK YOU https://stackoverflow.com/a/77297521 !!!!!!!
+
+const getProxyUrl = (request: Request) => {
+  const proxyUrl = new URL(import.meta.env.PUBLIC_PB_URL);
+  const requestUrl = new URL(request.url);
+
+  return new URL(requestUrl.pathname, proxyUrl);
+};
+
+export const ALL: APIRoute = async ({ request }) => {
+  const proxyUrl = getProxyUrl(request);
+  const response = await fetch(proxyUrl.href, request);
+  return new Response(response.body);
+};