Extract shared binary utility helpers into VG-Core

src/background.js

@@ -532,33 +532,6 @@ function decodeTcStringCoreMetadata(tcString) {
   }
 }
 
-function base64UrlToBits(value) {
-  const base64 = value
-    .replace(/-/g, "+")
-    .replace(/_/g, "/")
-    .padEnd(Math.ceil(value.length / 4) * 4, "=");
-
-  const binary = atob(base64);
-  let bits = "";
-
-  for (let index = 0; index < binary.length; index += 1) {
-    bits += binary
-      .charCodeAt(index)
-      .toString(2)
-      .padStart(8, "0");
-  }
-
-  return bits;
-}
-
-function bitsToInt(bits, start, length) {
-  return parseInt(bits.slice(start, start + length), 2);
-}
-
-function bitsToBoolean(bits, index) {
-  return bits[index] === "1";
-}
-
 function bitsToString(bits, start, length) {
   let result = "";