improvements: address requested changes

backend/src/lib/base64/index.ts

@@ -24,17 +24,5 @@ export const isBase64 = (
 };
 
 export const getBase64SizeInBytes = (base64String: string) => {
-  // Remove data URI scheme if present
-  const base64 = base64String.replace(/^data:.*?;base64,/, "");
-
-  // Remove padding characters
-  const withoutPadding = base64.replace(/=+$/, "");
-
-  // Calculate bits: each base64 character represents 6 bits
-  const totalBits = withoutPadding.length * 6;
-
-  // Convert bits to bytes (8 bits = 1 byte)
-  const bytes = totalBits / 8;
-
-  return bytes;
+  return Buffer.from(base64String, "base64").length;
 };