Fix port 4444 conflict: check existing jobs before starting multi/handler
(teamserver already runs handler via start_msf_server.sh — uzi must not start a second)
jobs.list values are str not dict — handle both types in isinstance check
Fix C2 SFTP ETXTBSY: rm -f remote_bin via SSH before sftp.put()
(prevents "text file busy" when overwriting a running payload binary)