fix: move paru repo config into moonarch.install to break bootstrap loop

The paru PKGBUILD repo config was only set up by post-install.sh and
transform.sh. If the config was missing on an existing system,
moonarch-git couldn't update — the fix required the package that
delivers the fix.

Now moonarch.install sets up the config on every install/upgrade.
post-install.sh keeps it for first-time bootstrap (before moonarch-git
exists). transform.sh no longer manages it.

scripts/post-install.sh

@@ -60,7 +60,7 @@ fi
 rm -f "$KEY_FILE"
 trap - EXIT
 
-# --- Set up Moonarch custom paru repo ---
+# --- Set up Moonarch custom paru repo (needed for first install bootstrap) ---
 
 log "Setting up Moonarch paru repo..."
 PARU_CONF="/etc/paru.conf"
@@ -80,7 +80,7 @@ fi
 
 paru -Syu --pkgbuilds --noconfirm
 
-# --- Install moonarch-git (pulls in all configs, scripts, themes as dependencies) ---
+# --- Install moonarch-git (subsequent updates handled by moonarch.install hook) ---
 
 log "Installing moonarch-git package..."
 paru -S --needed --noconfirm moonarch-git