feat(labelprint): 4x6 label print proxy on a Raspberry Pi

A Pi 3B+ (stickah.local) shares a Phomemo PM246 to the LAN as a plain CUPS
queue, so any machine can print 4x6 labels -- fulfillr-site's shipping labels
in particular -- without installing the vendor driver, which is x86-64 only.
The role builds the TSPL CUPS driver from source instead.

It is Debian, not Fedora, so it lives in its own inventory and playbook
(make deploy-labelprint / check-labelprint) and the home.debyl.io roles can
never run against it. make bootfs renders its cloud-init first-boot files onto
a freshly imaged SD card from the same templates the role uses. The Wi-Fi
credentials for the home and rescue networks are in the vault.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

ansible/roles/labelprint/templates/home-wifi.nmconnection.j2

@@ -0,0 +1,32 @@
+# {{ ansible_managed }}
+#
+# The normal, everyday Wi-Fi link. autoconnect-priority outranks anything
+# cloud-init/netplan rendered for the same SSID, so this is the profile
+# NetworkManager picks. autoconnect-retries=0 means retry forever rather than
+# giving up after four attempts and leaving the Pi off the network until
+# someone power-cycles it -- the rescue AP is the fallback, not the
+# destination.
+[connection]
+id=home-wifi
+uuid={{ (stickah_ssid ~ '-home-wifi') | to_uuid }}
+type=wifi
+interface-name=wlan0
+autoconnect=true
+autoconnect-priority=100
+autoconnect-retries=0
+
+[wifi]
+mode=infrastructure
+ssid={{ stickah_ssid }}
+
+[wifi-security]
+key-mgmt=wpa-psk
+# Accepts either a passphrase or the 64-hex precomputed PSK.
+psk={{ stickah_psk }}
+
+[ipv4]
+method=auto
+
+[ipv6]
+method=auto
+addr-gen-mode=default