refactor: deduplicate HEX64_REGEX to js/utils/hex.js

Moves the repeatedly defined HEX64_REGEX constant to a shared utility
module to improve maintainability and consistency. Updates all consumers
to import from the new location.

Signed-off-by: Jules <[email protected]>

Co-authored-by: PR0M3TH3AN <[email protected]>

js/utils/hex.js

@@ -1,3 +1,5 @@
+export const HEX64_REGEX = /^[0-9a-f]{64}$/i;
+
 export function normalizeHexString(value) {
   if (typeof value !== "string") {
     return "";

js/utils/profileBatchFetcher.js

@@ -3,9 +3,10 @@
 import { nostrClient } from "../nostrClientFacade.js";
 import { devLogger } from "./logger.js";
 import { fetchProfileMetadataBatch } from "../services/profileMetadataService.js";
+import { HEX64_REGEX } from "./hex.js";
 
 const DEFAULT_PROFILE_IMAGE = "assets/svg/default-profile.svg";
-const HEX64_REGEX = /^[0-9a-f]{64}$/i;
+
 
 export async function batchFetchProfilesFromRelays({
   authorSet,