fix(install): replace set-diff membership with per-package pacman -Qq --quiet query (deterministic)

scripts/install.sh

@@ -53,10 +53,10 @@ if [[ -f "$REPO/packages/aur.pkgs" ]]; then
   mapfile -t AUR_PKGS < <(read_manifest "$REPO/packages/aur.pkgs")
 fi
 
-mapfile -t INSTALLED < <(pacman -Qq | sort)
+# Membership via direct DB query per package — deterministic, no set-diff plumbing.
 DELTAC=()
 for p in "${PKGS[@]}"; do
-  printf '%s\n' "${INSTALLED[@]}" | grep -qx -- "$p" || DELTAC+=("$p")
+  pacman -Qq --quiet -- "$p" >/dev/null || DELTAC+=("$p")
 done
 
 echo "install.sh [$MODE] host=$HOST"
@@ -66,7 +66,7 @@ else
   echo "repo pkgs to install: ${DELTAC[*]}"
 fi
 for p in "${AUR_PKGS[@]}"; do
-  printf '%s\n' "${INSTALLED[@]}" | grep -qx -- "$p" || echo "aur pkg pending: $p"
+  pacman -Qq --quiet -- "$p" >/dev/null || echo "aur pkg pending: $p"
 done
 
 [[ "$MODE" == "check" ]] && exit 0