fix(release): stamping a payload snapshot skips the bootstrap-installer check

The payload snapshot omits apps/ (INERT_SNAPSHOT_DIRS), so validate_bootstrap_version
raised FileNotFoundError on every native bundle leg since dd72571178.

(cherry picked from commit 8411fdb333)

scripts/releases/stamping.py

@@ -83,7 +83,9 @@ def stamp(tree: Path, version: str, release_date: str) -> list[Path]:
         _rewrite(path, pattern, replacement, count=1, flags=flags)
         touch(path)
 
-    validate_bootstrap_version(tree, version)
+    # A payload snapshot omits apps/ (INERT_SNAPSHOT_DIRS); it carries no installer to disagree with.
+    if (tree / "apps" / "bootstrap-installer").is_dir():
+        validate_bootstrap_version(tree, version)
     return written
 
 

tests/scripts/test_version_stamping.py

@@ -91,3 +91,17 @@ def test_stamping_writes_the_build_tree_and_leaves_the_source_tree(tmp_path, mon
     from scripts.releases.stamping import validate_bootstrap_version
     with pytest.raises(ValueError, match="Tauri config"):
         validate_bootstrap_version(build, "0.21.5")
+
+
+def test_stamping_a_payload_snapshot_without_apps_stamps_the_runtime(tmp_path):
+    """The bundled payload snapshot drops apps/ (INERT_SNAPSHOT_DIRS), so it has no installer to validate."""
+    import shutil
+
+    from scripts.releases.stamping import stamp
+
+    _tree(tmp_path)
+    shutil.rmtree(tmp_path / "apps")
+
+    stamp(tmp_path, "0.21.5", "2026.9.22")
+
+    assert 'version = "0.21.5"' in (tmp_path / "pyproject.toml").read_text(encoding="utf-8")