fix(seed): correct sys.path so seed_email_templates_core can import app.*

Script lived at scripts/seed/seed_email_templates_core.py and inserted
Path(__file__).parent.parent into sys.path — that resolves to
scripts/, not the project root, so `from app.core.database import get_db`
raises ModuleNotFoundError when run from inside the container.

The loyalty sibling already uses parent.parent.parent correctly.
Hit during the FR/DE password_reset reseed on prod.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

scripts/seed/seed_email_templates_core.py

@@ -10,8 +10,8 @@ import json
 import sys
 from pathlib import Path
 
-# Add project root to path
-sys.path.insert(0, str(Path(__file__).parent.parent))
+# Add project root to path (script is at scripts/seed/, project root is two levels up)
+sys.path.insert(0, str(Path(__file__).parent.parent.parent))
 
 # Register all models with SQLAlchemy so string-based relationships resolve
 for _mod in [