JobKorea part-time jobs Korea jobs in Korea for foreigners change job korea visa KOTRA job fair work visa korea freelance jobs Korea Saramin employer shutdown foreign worker Korea foreign worker ghosted Korea Seoul Global Center XpatJobs korea employment visa foreigner jobs Seoul fired in Korea visa resigning job korea job termination Korea foreigner quitting job Korea foreigner foreign worker resignation LinkedIn Korea work visa korea rules work in South Korea 2025 work visa status Korea job search guide teaching jobs Korea notice period korea non-teaching jobs Korea English jobs Korea foreign worker job change company closed Korea visa Kowork expat career Korea employer no response Korea visa sponsorship Korea Korea job platforms unpaid salary Korea foreigner