fix: correct worker indentation and stabilize startup

SFTP: add store + worker /sftp-test

fix: handle id vs job_id from API

fix: worker uses X-Worker-Token header

fix: install worker deps via requirements.txt

fix: add requests dependency to worker

phase3: worker polls API job queue

fix: add /health http server so HF marks worker Running

fix: add worker deps

fix: force long-running worker process

init: worker docker skeleton

initial commit