improve version and mirror updating

updates.d/10-pacman.sh

@@ -17,6 +17,13 @@ remove_flatpaks "${REMOVE_FLATPAKS[@]}"
 echo "Checking the Federated Computer package repo..."
 ensure_federated_repo || STATUS=1
 
+# A stale mirror hides new packages instead of failing, so pick fresh ones
+# before syncing. mirrors.sh also sets up reflector on machines without it.
+if age="$(mirror_age_hours)" && (( age >= MIRROR_STALE_HOURS )); then
+  echo "Your package mirror ($(first_mirror)) last synced with Arch $age hours ago."
+  bash "$COREDESKTOP/system/mirrors.sh"
+fi
+
 # A machine that hasn't updated in a while can have a keyring too old to verify
 # the new packages. Update it first; the -Su below completes this -Sy.
 echo "Updating Arch keyring..."