IPv6 on, forgetest dual-stack, the release rootfs sheds 22 MB

The distro keeps its ipv6 feature (busybox networking and ifupdown
inet6, openssh, ntp and rsyslog follow); forgetest binds "::" by
default, one dual-stack socket that still serves IPv4. The release
image drops nano (with it file and the libmagic database, 8.7 MB; the
dev image keeps nano), the udev hardware database (7.7 MB of USB and
PCI identities for buses the board lacks, via BAD_RECOMMENDATIONS) and
urllib3's pyOpenSSL/cryptography recommendation (6 MB; nothing imports
them, TLS goes through the standard library). BRINGUP item 21 records
the round and the bench checks it owes; item 16 gets its re-measure
plan on the UP kernel with the performance governor.

Coverage: image.* covers the rootfs composition and the distro conf
(platform); forgetest's own suite covers the server.

meta-forgefirm/recipes-forgefirm/images/forgefirm-image-dev.bb

@@ -12,6 +12,7 @@ IMAGE_INSTALL += " \
   forgetest \
   python3-gfutilities-emulator \
   htop \
+  nano \
 "
 
 # debug-tweaks (passwordless root, root SSH login) belongs ONLY to the dev

meta-forgefirm/recipes-forgefirm/images/forgefirm-image.bb

@@ -10,8 +10,10 @@ DESCRIPTION = "OpenGlow/ForgeFIRM image for Glowforge"
 # (gfui-client connects to Glowforge's servers). Removing it here (override
 # only; the shared glowforge-image base is untouched) also sidesteps its
 # do_package failure. Its role is filled locally by forgectrl and the
-# controllers below.
-IMAGE_INSTALL:remove = "gfui-client"
+# controllers below. nano is a bench convenience (the dev image keeps it);
+# on the release rootfs it costs 8.7 MB, most of it libmagic and its
+# database, which nothing else here uses.
+IMAGE_INSTALL:remove = "gfui-client nano"
 
 # grblhal-glowforge: the grblHAL motion controller (Grbl over TCP:23).
 # forgectrl: the ForgeFIRM machine-services daemon (HTTP :8080): controller