BREAKING_CHANGE(iso): rename pathJoin to join for better API consistency

ts_iso/index.ts

@@ -4,7 +4,7 @@
  * @param segments - Path segments to join
  * @returns Joined path string
  */
-export function pathJoin(...segments: string[]): string {
+export function join(...segments: string[]): string {
   // Filter out empty strings and non-string values
   const validSegments = segments.filter(segment => 
     typeof segment === 'string' && segment.length > 0