feat: add legacy tg-shop migration to installer

tests/test_install_script.py

@@ -21,6 +21,7 @@ def test_shell_installer_help_does_not_require_python():
 
     assert "MINISHOP_INSTALL_REPO" in result.stdout
     assert "dry-run" in result.stdout
+    assert "LEGACY_TGSHOP_SOURCE_DSN" in result.stdout
 
 
 def test_shell_installer_is_the_only_install_entrypoint():
@@ -37,3 +38,13 @@ def test_shell_installer_downloads_raw_files_and_runs_import_in_container():
     assert "backend python backend/scripts/import_legacy.py" in script
     assert "--dry-run" in script
     assert "Install new stack and run legacy migration" in script
+
+
+def test_shell_installer_supports_legacy_tgshop_volume_and_dsn_paths():
+    script = INSTALL_SCRIPT.read_text(encoding="utf-8")
+
+    assert "Legacy remnawave-tg-shop" in script
+    assert "remnawave-tg-shop-db-data" in script
+    assert "remnawave-minishop-db-data" in script
+    assert "pg_dump --clean --if-exists" in script
+    assert "run_compose run --rm migrate" in script