feat: replace serial automation with resident TCP agent

fec/tcp-stage.bat

@@ -1,19 +0,0 @@
-@echo off
-rem Pull a host-built TCP staging bundle into the authoritative C:\FEC tree.
-rem QEMU user networking exposes the host as 10.0.2.2.  HTGET and UNZIP are
-rem supplied by the installed FreeDOS network tools.
-if "%1"=="" goto usage
-if exist C:\FEC\STAGE.ZIP del C:\FEC\STAGE.ZIP
-htget -o C:\FEC\STAGE.ZIP %1
-if errorlevel 1 goto fail
-unzip -o C:\FEC\STAGE.ZIP -d C:\FEC
-if errorlevel 1 goto fail
-if exist C:\FEC\TCPSTG.OK del C:\FEC\TCPSTG.OK
-echo OK>C:\FEC\TCPSTG.OK
-goto done
-:usage
-echo usage: TCP-STAGE.BAT http://10.0.2.2:8000/STAGE.ZIP
-goto done
-:fail
-echo FAIL>C:\FEC\TCPSTG.FAIL
-:done