feat: ship minecraft theme updates and platform workflow improvements

frontend/src/app/api/image-cache/route.ts

@@ -8,6 +8,16 @@ export const runtime = "nodejs";
 
 const CACHE_DIR = process.env.CSP_IMAGE_CACHE_DIR ?? "/tmp/csp-image-cache";
 const MAX_BYTES = 5 * 1024 * 1024;
+const IMAGE_EXT_TO_TYPE: Record<string, string> = {
+  ".png": "image/png",
+  ".jpg": "image/jpeg",
+  ".jpeg": "image/jpeg",
+  ".webp": "image/webp",
+  ".gif": "image/gif",
+  ".svg": "image/svg+xml",
+  ".bmp": "image/bmp",
+  ".ico": "image/x-icon",
+};
 
 function toArrayBuffer(view: Uint8Array): ArrayBuffer {
   return view.buffer.slice(
@@ -28,6 +38,25 @@ function pickExt(urlObj: URL, contentType: string): string {
   return ".img";
 }
 
+function inferImageType(urlObj: URL, contentType: string): string {
+  const raw = contentType.split(";")[0].trim().toLowerCase();
+  if (raw.startsWith("image/")) return raw;
+  const ext = path.extname(urlObj.pathname || "").toLowerCase();
+  return IMAGE_EXT_TO_TYPE[ext] ?? raw;
+}
+
+function looksLikeImage(urlObj: URL, contentType: string): boolean {
+  if (contentType.startsWith("image/")) return true;
+  const ext = path.extname(urlObj.pathname || "").toLowerCase();
+  return Boolean(IMAGE_EXT_TO_TYPE[ext]);
+}
+
+function redirectToTarget(target: URL): NextResponse {
+  const res = NextResponse.redirect(target.toString(), 307);
+  res.headers.set("Cache-Control", "no-store");
+  return res;
+}
+
 async function readCachedByKey(
   key: string
 ): Promise<{ data: Uint8Array; contentType: string } | null> {
@@ -94,14 +123,12 @@ export async function GET(req: NextRequest) {
     });
 
     if (!resp.ok) {
-      return NextResponse.json(
-        { ok: false, error: `fetch image failed: HTTP ${resp.status}` },
-        { status: 502 }
-      );
+      return redirectToTarget(target);
     }
 
-    const contentType = (resp.headers.get("content-type") ?? "").toLowerCase();
-    if (!contentType.startsWith("image/")) {
+    const headerType = (resp.headers.get("content-type") ?? "").toLowerCase();
+    const contentType = inferImageType(target, headerType);
+    if (!looksLikeImage(target, contentType)) {
       return NextResponse.json({ ok: false, error: "url is not an image" }, { status: 400 });
     }
 
@@ -125,11 +152,8 @@ export async function GET(req: NextRequest) {
         "Cache-Control": "public, max-age=31536000, immutable",
       },
     });
-  } catch (e: unknown) {
-    return NextResponse.json(
-      { ok: false, error: `fetch image failed: ${String(e)}` },
-      { status: 502 }
-    );
+  } catch {
+    return redirectToTarget(target);
   } finally {
     clearTimeout(timer);
   }