test: importing the RTC copy E2E script must not change the environment (credential test isolation)

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

scripts/rtc_copy_write_e2e.py

@@ -21,7 +21,6 @@ ROOT = Path(__file__).resolve().parents[1]
 sys.path.insert(0, str(ROOT)); sys.path.insert(0, str(ROOT / "scripts")); sys.path.insert(0, str(ROOT / "agent" / "src"))
 from dotenv import load_dotenv  # noqa: E402
 
-load_dotenv(ROOT / ".env")
 import fdb  # noqa: E402
 import local_completion as lc  # noqa: E402
 from central.app.operational_state import classify_product_state, summarize_operational_states  # noqa: E402
@@ -79,6 +78,7 @@ def coverage(env, company, ncm_valid, override=None):
 
 
 def main():
+    load_dotenv(ROOT / ".env")            # credentials only when the script runs, never as an import side effect
     guard(COPY)
     service = load_service()
     env = {"FIREBIRD_DATABASE_PATH": COPY, "FB_USER": os.environ["FB_USER"], "FB_PASSWORD": os.environ["FB_PASSWORD"], "FIREBIRD_CLIENT_LIBRARY": os.environ.get("FIREBIRD_CLIENT_LIBRARY")}