fix: relocate long-path runtime console launchers

Assistant: codex
Assistant-Model: gpt-6-astra
Assistant-Session: 01a0e387-534d-70e3-ad53-4ea05676db8c

tests/test_runtime_builder.py

@@ -96,3 +96,44 @@ def test_installed_package_contents_must_match_committed_source(tmp_path, change
     else:
         result = builder.verify_source_files(site, [(source, "fixture", "fixture")])
         assert result["files_verified"] == 1
+
+
+@pytest.mark.parametrize("launcher", ["direct", "long-path", "spaces"])
+def test_console_entrypoint_runs_after_build_directory_disappears(tmp_path, monkeypatch, launcher):
+    import shutil
+    import subprocess
+    import sys
+
+    name = {"long-path": "long-" + "x" * 150, "spaces": "build with spaces"}.get(
+        launcher, "build"
+    )
+    output = tmp_path / name
+    (output / "bin").mkdir(parents=True)
+    shutil.copy2(sys.executable, output / "bin/python3")
+    interpreter = str(output / "bin/python3")
+    body = "print('entrypoint-ok')\n"
+    if launcher == "direct":
+        header = f"#!{interpreter}\n"
+    else:
+        header = "#!/bin/sh\n'''exec' '" + interpreter + "' \"$0\" \"$@\"\n' '''\n"
+    command = output / "bin/rein-aharness"
+    command.write_text(header + body)
+    command.chmod(0o755)
+    binary = output / "bin/native"
+    binary.write_bytes(b"\x7fELF\x00leave unchanged")
+    mount = tmp_path / "mounted"
+    monkeypatch.setattr(builder, "RUNTIME_MOUNT", str(mount))
+    assert builder.relocate_entrypoints(output) == ["rein-aharness"]
+    shutil.move(output, mount)
+    assert not output.exists()
+    result = subprocess.run([str(mount / "bin/rein-aharness")], capture_output=True, text=True)
+    assert result.returncode == 0, result.stderr
+    assert result.stdout.strip() == "entrypoint-ok"
+    assert (mount / "bin/native").read_bytes() == b"\x7fELF\x00leave unchanged"
+
+
+def test_unknown_governed_launcher_fails_closed(tmp_path):
+    (tmp_path / "bin").mkdir()
+    (tmp_path / "bin/rein-aharness").write_text("#!/bin/sh\nexec /unreviewed/python3\n")
+    with pytest.raises(ValueError, match="unrelocated governed entrypoint"):
+        builder.relocate_entrypoints(tmp_path)