feat(ramfs): switch to text console before flashing

When the target device runs a graphical desktop, the flash helper's
console output is hidden behind the GUI. Switch to VT1 in Phase 1
(before re-exec) so the physical display shows flashing progress and
gives a clear visual signal that something drastic is happening.

Uses the system chvt command (still available from rootfs in Phase 1).
Silently ignored on headless devices or when VTs are unavailable.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: mairas

flash-live-system

@@ -700,12 +700,15 @@ deploy_ramfs_helper() {
 #!/bin/bash
 
 # Phase 1 — runs under /bin/bash from rootfs (safe: dd hasn't started yet).
-# Re-exec under busybox sh from tmpfs so that NOTHING running after dd
+# Switch to a text console so output is visible on the physical display
+# (also serves as a clear visual signal that something drastic is happening).
+# Then re-exec under busybox sh from tmpfs so that NOTHING running after dd
 # depends on rootfs pages. Output is piped through tee so it appears on
 # both /dev/console (physical display) and /dev/shm/flash-helper.log.
 
 if [ -z "$_FLASH_REEXEC" ]; then
   export _FLASH_REEXEC=1
+  chvt 1 2>/dev/null || true
   exec /dev/shm/busybox sh -c \
     '/dev/shm/busybox sh "$0" "$@" 2>&1 | /dev/shm/busybox tee /dev/shm/flash-helper.log > /dev/console' \
     "$0" "$@"