fix: resolve TypeScript and lint issues

- Fix proxy routes to use resolveImagerBase instead of removed resolveUpstreamBase
- Fix avatarImageUrl type signature to use AvatarOptions
- Run biome formatter

src/app/api/imaging/avatar/route.ts

@@ -1,5 +1,5 @@
 import { type NextRequest, NextResponse } from "next/server";
-import { resolveUpstreamBase } from "@/lib/imager";
+import { resolveImagerBase } from "@/lib/imager";
 
 const FIGURE_RE = /^([a-z]{2}-\d+)(\.[a-z]{2}-\d+)*$/i;
 const FIGURE_MAX_LEN = 512;
@@ -66,7 +66,7 @@ export async function GET(request: NextRequest) {
 	const imgFormat = searchParams.get("img_format");
 	if (imgFormat) params.set("img_format", imgFormat);
 
-	const upstream = resolveUpstreamBase();
+	const upstream = resolveImagerBase();
 	const upstreamUrl = `${upstream}?${params.toString()}`;
 
 	try {