refactor(tests): add shared CLI test helpers

Adds shared test helpers for CLI script loading and scoped core.database stubs, then converts a low-conflict pilot set of CLI tests. Part of #2523.

tests/helpers/cli_loader.py

@@ -0,0 +1,25 @@
+"""Shared loader for CLI scripts under scripts/."""
+import importlib.machinery
+import importlib.util
+from pathlib import Path
+
+
+_SCRIPTS_DIR = Path(__file__).resolve().parents[2] / "scripts"
+
+
+def load_script(script_name):
+    """Load a script from scripts/ by name and return it as a module.
+
+    The module name is derived from the script name (hyphens become underscores,
+    with a _cli suffix) giving each script a stable, unique import identity.
+
+    Any sys.modules stubs the script needs at import time must be injected via
+    monkeypatch before calling this function.
+    """
+    module_name = script_name.replace("-", "_") + "_cli"
+    path = _SCRIPTS_DIR / script_name
+    loader = importlib.machinery.SourceFileLoader(module_name, str(path))
+    spec = importlib.util.spec_from_loader(loader.name, loader)
+    module = importlib.util.module_from_spec(spec)
+    loader.exec_module(module)
+    return module