Configure robust guest_login retrieval and database field defaults

app/routers/auth.py

@@ -92,7 +92,13 @@ async def update_mode(body: schemas.ModeUpdate, current_user: models.User = Depe
 
 @router.post("/guest", response_model=schemas.UserResponse)
 async def guest_login(response: Response, db: AsyncSession = Depends(get_db)):
-    result = await db.execute(select(models.User).where(models.User.firebase_uid == "guest_uid_123"))
+    # Look up by either UID or email to prevent uniqueness conflicts if rows already exist
+    result = await db.execute(
+        select(models.User).where(
+            (models.User.firebase_uid == "guest_uid_123") | 
+            (models.User.email == "guest@archvise.com")
+        )
+    )
     user = result.scalars().first()
     
     if not user:
@@ -105,17 +111,46 @@ async def guest_login(response: Response, db: AsyncSession = Depends(get_db)):
             display_mode="founder",
             credits_remaining=999999,
             credits_reset_at=datetime.utcnow() + timedelta(days=30),
+            github_connected=False,
+            total_audits=0,
+            total_designs=0,
             is_active=True
         )
         db.add(user)
         await db.commit()
         await db.refresh(user)
-    elif user.plan != "pro" or user.credits_remaining != 999999:
-        user.plan = "pro"
-        user.credits_remaining = 999999
-        db.add(user)
-        await db.commit()
-        await db.refresh(user)
+    else:
+        # Guarantee all non-nullable schema fields are populated on the existing guest user
+        dirty = False
+        if user.firebase_uid != "guest_uid_123":
+            user.firebase_uid = "guest_uid_123"
+            dirty = True
+        if user.email != "guest@archvise.com":
+            user.email = "guest@archvise.com"
+            dirty = True
+        if user.plan != "pro":
+            user.plan = "pro"
+            dirty = True
+        if user.credits_remaining != 999999:
+            user.credits_remaining = 999999
+            dirty = True
+        if user.github_connected is None:
+            user.github_connected = False
+            dirty = True
+        if user.total_audits is None:
+            user.total_audits = 0
+            dirty = True
+        if user.total_designs is None:
+            user.total_designs = 0
+            dirty = True
+        if user.is_active is None:
+            user.is_active = True
+            dirty = True
+            
+        if dirty:
+            db.add(user)
+            await db.commit()
+            await db.refresh(user)
 
     response.set_cookie(
         key="archvise_session",