Authz Check

The most common security hole: the code checks you're logged IN, but not that you OWN the thing.

• For every resource access: does it verify the current user is allowed THIS specific record? WHERE id = ? AND owner_id = current_user — not just WHERE id = ?.
• IDOR test: swap the ID in the request to another user's. Does it leak/allow?
• Admin/privileged actions: is the role checked server-side, every time, not just hidden in the UI?
• Default deny: new endpoints should require explicit authorization, not be open by oversight. Output each handler that authenticates but doesn't authorize, with the missing check.