Add pre-refresh-pacman.d hooks for custom repository support (#5681)

Fires after the channel template is copied to /etc/pacman.conf and before
`pacman -Syyuu` runs, letting users layer custom Pacman repositories or
IgnorePkg directives onto the freshly-written config so they're respected
by the upgrade. Useful for users running on overlay distros (CachyOS,
Chaotic-AUR, internal company repos) where a wipe-and-reinstall would
otherwise pull vanilla Arch versions.

Ships with `pre-refresh-pacman.d/add-custom-repo.sample` showing the
pattern.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

bin/omarchy-refresh-pacman

@@ -19,5 +19,8 @@ echo
 sudo cp -f "$OMARCHY_PATH/default/pacman/pacman-$channel.conf" /etc/pacman.conf
 sudo cp -f "$OMARCHY_PATH/default/pacman/mirrorlist-$channel" /etc/pacman.d/mirrorlist
 
+# Allow user customization of /etc/pacman.conf before the upgrade runs
+omarchy-hook pre-refresh-pacman
+
 # Reset all package DBs and then update
 sudo pacman -Syyuu --noconfirm

config/omarchy/hooks/pre-refresh-pacman.d/add-custom-repo.sample

@@ -0,0 +1,24 @@
+#!/bin/bash
+
+# This hook is called by `omarchy refresh pacman` AFTER the channel template
+# is copied to /etc/pacman.conf and BEFORE `pacman -Syyuu` runs. Use it to
+# layer customizations onto the freshly-written pacman.conf so they're
+# respected by the upgrade — common cases are adding a custom repository
+# (e.g. CachyOS, Chaotic-AUR, an internal company repo) or extra IgnorePkg
+# lines.
+#
+# The hook runs as the invoking user with a warm sudo cache.
+#
+# To put it into use, remove .sample from this file name.
+
+# Example: add an Include line above [core] for a custom repo.
+# Maintain the repo entries in /etc/pacman.d/custom-repos.conf yourself.
+
+CONF=/etc/pacman.conf
+SNIPPET=/etc/pacman.d/custom-repos.conf
+MARKER="Include = $SNIPPET"
+
+[[ -r $SNIPPET ]] || exit 0
+grep -qxF "$MARKER" "$CONF" && exit 0
+
+sudo sed -i "0,/^\[core\]/s||$MARKER\n\n[core]|" "$CONF"