Backfill default portfolios for existing users on startup.

On app boot, create a Default Portfolio for any user account that has none, including early Clerk test signups.

Co-authored-by: Cursor <cursoragent@cursor.com>

db.py

@@ -77,6 +77,7 @@ async def init_db():
     await sync_stock_fundamental_seed_data()
     await sync_stock_dividend_seed_data()
     await ensure_default_admin_user()
+    await ensure_default_portfolios_for_users()
 
 
 async def close_db():
@@ -149,6 +150,21 @@ async def ensure_default_admin_user():
         return
 
 
+async def ensure_default_portfolios_for_users():
+    """Create a default portfolio for any user that has none (e.g. early Clerk signups)."""
+    try:
+        from App.routers.users.models import User
+        from App.routers.portfolio.models import Portfolio
+
+        users = await User.all()
+        for user in users:
+            has_portfolio = await Portfolio.filter(user=user).exists()
+            if not has_portfolio:
+                await Portfolio.create(user=user, name="Default Portfolio")
+    except Exception:
+        return
+
+
 async def sync_stock_company_seed_data():
     """Populate curated stock company metadata from bundled research JSON."""
     try: