refactor(deploy): share UP Board serial hardware between installed + live ISO

The sintra live ISO (live.nix) had no serial support — ftdi_sio and the
ttyJ5/ttyJ7 udev symlinks were only in hardware/upboard.nix (installed), so
booting iso-sintra on real hardware failed on the validator + F56 dispenser
while the disk image worked. The two definitions had already drifted (live's
tejo block lacked ttyS4).

Extract the UP Board serial peripherals (usbserial/ftdi_sio/cp210x, the
ttyJ4/ttyJ5/ttyJ7 udev symlinks + permissions, console=tty0) into
hardware/upboard-serial.nix and import it from both upboard.nix (installed
tejo + sintra) and live.nix (sintra only). Single source of truth — the two
artifacts can't drift again. Named upboard-serial (not sintra-serial) since
upboard.nix serves both tejo-installed and sintra-installed.

Camera + LED/SPI rules stay inline in upboard.nix (installed-specific; the
pairing camera works via getUserMedia without the scanner symlink). Verified
by eval: live sintra now carries ftdi_sio + console=tty0 + ttyJ7; installed
sintra/tejo unchanged (serial present, camera present, no console dupe).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

deploy/nixos/hardware/upboard.nix

@@ -11,6 +11,10 @@
 { config, lib, pkgs, ... }:
 
 {
+  # Serial peripherals (validator/dispenser/printer modules + udev symlinks +
+  # console=tty0) are shared with the live ISO via ./upboard-serial.nix.
+  imports = [ ./upboard-serial.nix ];
+
   boot = {
     loader = {
       systemd-boot.enable = true;
@@ -42,21 +46,12 @@
       "kvm-intel"
       "i2c-dev"
       "spi-dev"
-      "usbserial" # USB-to-serial adapters
-      "ftdi_sio" # FTDI USB serial
-      "cp210x" # CP210x USB serial
+      # Serial modules (usbserial/ftdi_sio/cp210x) → ./upboard-serial.nix.
     ];
 
     kernelParams = [
       "i915.enable_psr=0"
-      # NOTE: do NOT route the kernel console through ttyS4 on Sintra.
-      # ttyS4 is the SoC's MMIO 16550A (the only real UART besides the
-      # legacy ttyS0 at I/O 0x3f8) and is wired to the Fujitsu F56
-      # dispenser's RS-232 header on Sintra. Holding it as console
-      # prevents userspace from opening it at 9600 baud and HAL fails
-      # with "Input/output error setting custom baud rate of 9600".
-      # If you want serial debug, point console at ttyS0 instead.
-      "console=tty0"
+      # console=tty0 (keeps ttyS4 free for the F56) → ./upboard-serial.nix.
       "quiet"
       "splash"
     ];
@@ -104,37 +99,9 @@
     hybrid-sleep.enable = false;
   };
 
-  # Serial port permissions + tejo-specific symlinks
+  # Camera + LED/SPI peripherals. The serial rules (validator/dispenser/printer
+  # symlinks + permissions) are shared with the live ISO in ./upboard-serial.nix.
   services.udev.extraRules = lib.mkAfter ''
-    # Generic serial port permissions
-    KERNEL=="ttyS[0-9]*", MODE="0666"
-    KERNEL=="ttyUSB[0-9]*", MODE="0666"
-    KERNEL=="ttyACM[0-9]*", MODE="0666"
-
-    # ── Tejo serial port symlinks ──────────────────────────────────────
-    # Both UP Board and UP4000 rules included (match different kernel paths)
-
-    # Printer (ttyJ4)
-    KERNELS=="1-7.2:1.0", SYMLINK+="ttyJ4"
-    KERNEL=="ttyUSB0", SYMLINK+="ttyJ4"
-
-    # Validator (ttyJ5)
-    KERNELS=="1-7.3:1.0", SYMLINK+="ttyJ5"
-    KERNEL=="ttyUSB1", SYMLINK+="ttyJ5"
-
-    # Dispenser (ttyJ7).
-    # ttyS1 / ttyS5 cover earlier UP Board variants where the dispenser
-    # lands on those kernel-enumerated serial nodes; ttyS4 covers the
-    # Sintra (UP Board Atom/Apollo Lake) where the dispenser is wired
-    # to the SoC's MMIO UART. Whichever device actually exists at
-    # runtime gets the ttyJ7 symlink.
-    KERNEL=="ttyS1", SYMLINK+="ttyJ7"
-    KERNEL=="ttyS4", SYMLINK+="ttyJ7"
-    KERNEL=="ttyS5", SYMLINK+="ttyJ7"
-
-    # Legacy ttyAMA0 alias
-    SUBSYSTEM=="tty", KERNEL=="ttyS1", SYMLINK+="ttyAMA0", GROUP="dialout"
-
     # ── Camera devices ─────────────────────────────────────────────────
     SUBSYSTEM=="video4linux", ATTR{index}=="0", KERNELS=="1-5", ATTRS{idVendor}=="0ac8", ATTRS{idProduct}=="0345", SYMLINK+="video-scan"
     SUBSYSTEM=="video4linux", ATTR{index}=="0", KERNELS=="1-2", ATTRS{idVendor}=="0ac8", ATTRS{idProduct}=="0345", SYMLINK+="video-scan"
@@ -147,8 +114,5 @@
     SUBSYSTEM=="spidev", GROUP="spi", MODE="0660"
     SUBSYSTEM=="i2c-dev", GROUP="i2c", MODE="0660"
     SUBSYSTEM=="leds", KERNEL=="upboard:*", ACTION=="add|change", RUN+="${pkgs.findutils}/bin/find /sys$devpath -type f -exec ${pkgs.coreutils}/bin/chmod g+u {} + -exec ${pkgs.coreutils}/bin/chown :leds {} +"
-
-    # Disable USB autosuspend (prevents serial adapters from sleeping)
-    ACTION=="add", SUBSYSTEM=="usb", TEST=="power/control", ATTR{power/control}="on"
   '';
 }