fix: add .dockerignore and env_file to docker-compose

Prevents .env from being baked into Docker image (was overriding
config defaults). Adds env_file directive so containers load host
.env properly.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/modules/messaging/tests/unit/test_store_email_settings_service.py

@@ -33,7 +33,7 @@ def test_email_settings(db, test_store):
         smtp_host="smtp.example.com",
         smtp_port=587,
         smtp_username="testuser",
-        smtp_password="testpass",
+        smtp_password="testpass",  # noqa: SEC-001
         smtp_use_tls=True,
         smtp_use_ssl=False,
         is_configured=True,
@@ -56,7 +56,7 @@ def test_verified_email_settings(db, test_store):
         smtp_host="smtp.example.com",
         smtp_port=587,
         smtp_username="testuser",
-        smtp_password="testpass",
+        smtp_password="testpass",  # noqa: SEC-001
         smtp_use_tls=True,
         is_configured=True,
         is_verified=True,
@@ -155,7 +155,7 @@ class TestStoreEmailSettingsWrite:
             "smtp_host": "smtp.example.com",
             "smtp_port": 587,
             "smtp_username": "user",
-            "smtp_password": "pass",
+            "smtp_password": "pass",  # noqa: SEC-001
         }
 
         settings = store_email_settings_service.create_or_update(