test: move area_cli tests into cli directory (#3842)

* test: move area_cli tests into cli directory

* test: include research CLI status in cli test move

tests/cli/test_signature_cli_export.py

@@ -0,0 +1,45 @@
+import sys
+from types import ModuleType
+
+from tests.helpers.cli_loader import load_script
+
+
+def _load_signature_cli(monkeypatch):
+    sqlalchemy_mod = ModuleType("sqlalchemy")
+    sqlalchemy_mod.text = lambda value: value
+    core_mod = ModuleType("core")
+    database_mod = ModuleType("core.database")
+    database_mod.engine = object()
+    monkeypatch.setitem(sys.modules, "sqlalchemy", sqlalchemy_mod)
+    monkeypatch.setitem(sys.modules, "core", core_mod)
+    monkeypatch.setitem(sys.modules, "core.database", database_mod)
+    return load_script("odysseus-signature")
+
+
+def test_decode_png_data_accepts_data_url(monkeypatch):
+    cli = _load_signature_cli(monkeypatch)
+
+    png = b"\x89PNG\r\n\x1a\nrest"
+    assert cli._decode_png_data("data:image/png;base64,iVBORw0KGgpyZXN0") == png
+
+
+def test_decode_png_data_rejects_invalid_base64(monkeypatch):
+    cli = _load_signature_cli(monkeypatch)
+
+    try:
+        cli._decode_png_data("not valid!!!")
+    except SystemExit as exc:
+        assert exc.code == 1
+    else:
+        raise AssertionError("expected invalid base64 to exit")
+
+
+def test_decode_png_data_rejects_non_png_bytes(monkeypatch):
+    cli = _load_signature_cli(monkeypatch)
+
+    try:
+        cli._decode_png_data("aGVsbG8=")
+    except SystemExit as exc:
+        assert exc.code == 1
+    else:
+        raise AssertionError("expected non-PNG bytes to exit")