iso/pacman.conf: document optional NoExtract size levers

Commented-out only. Keep the bakery-vs-pacman and SigLevel = Never
honesty comments already on main.

iso/pacman.conf

@@ -9,6 +9,23 @@ Architecture = auto
 CheckSpace
 ParallelDownloads = 5
 
+# Optional NoExtract size levers — left disabled. This file is both the ISO
+# build config AND the installed system's pacman.conf, so enabling any line
+# also stops future pacman -Syu from restoring those files.
+# Measured against the 844-package closure (xz squashfs, profiledef.sh opts):
+#   usr/share/locale (non-en)  405.0 MiB raw -> 92.28 MiB ISO
+#   usr/share/doc              130.5 MiB raw -> 26.54 MiB ISO
+#   usr/share/man               41.5 MiB raw -> 38.77 MiB ISO
+#   usr/share/info              12.9 MiB raw -> 11.12 MiB ISO
+#   usr/share/gtk-doc           16.0 MiB raw ->  1.18 MiB ISO
+#   usr/include                193.6 MiB raw -> 25.26 MiB ISO
+# Non-en locales make every GUI English-only until the package is reinstalled
+# without this NoExtract; dropping man/info means `man` returns nothing.
+#NoExtract   = usr/share/locale/* !usr/share/locale/en* !usr/share/locale/locale.alias
+#NoExtract   = usr/share/doc/* usr/share/gtk-doc/* usr/share/info/*
+#NoExtract   = usr/share/man/*
+#NoExtract   = usr/include/*
+
 Color
 VerbosePkgLists
 ILoveCandy