fix(install): root-side flake refs must be path:, not git+file

The chown fix made the flake user-owned, and root's libgit2 then refuses
git+file fetches of it ("not owned by current user") — which silently
killed the seeding step under set -e and would equally break
nixos-install --flake. Use path: refs for the live-side archive and the
nixos-install invocation (path flakes read flake.lock, skip libgit2),
and make seeding failure non-fatal as intended.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

pkgs/nomarchy-install/nomarchy-install.sh

@@ -425,15 +425,17 @@ section "Installing (this takes a while)"
 # `flake archive --to` enforces signatures and locally-evaluated source
 # paths have none; plain `nix copy` accepts --no-check-sigs.
 info "Seeding flake inputs into the target store..."
+# path: (not git+file) — the flake dir is owned by the target user and
+# root's libgit2 refuses repositories owned by someone else.
 flake_paths=$(nix --extra-experimental-features "nix-command flakes" \
-    flake archive --json "$FLAKE_DIR" 2>/dev/null \
+    flake archive --json "path:$FLAKE_DIR" \
     | python3 -c '
 import json, sys
 def walk(node):
     yield node["path"]
     for child in node.get("inputs", {}).values():
         yield from walk(child)
-print("\n".join(walk(json.load(sys.stdin))))')
+print("\n".join(walk(json.load(sys.stdin))))' || true)
 if [[ -n "$flake_paths" ]]; then
     # shellcheck disable=SC2086
     nix --extra-experimental-features "nix-command flakes" \
@@ -455,7 +457,7 @@ if [[ ${#NIXOS_INSTALL_OPTS[@]} -gt 0 ]]; then
         copy --all --no-check-sigs --to "local?root=/mnt"
 fi
 
-nixos-install --no-root-passwd "${NIXOS_INSTALL_OPTS[@]}" --flake "$FLAKE_DIR#default"
+nixos-install --no-root-passwd "${NIXOS_INSTALL_OPTS[@]}" --flake "path:$FLAKE_DIR#default"
 success "System installed (bootloader in place)"
 
 # Pre-activate the Home Manager generation so the FIRST boot lands in the