Session model auto-switched from default to Opus during routine permissions/RBAC coding — likely safety-classifier false positive

Summary

During an ordinary coding session, the session model unexpectedly switched from my configured default (Fable 5) to Opus without my issuing any /model command. I believe this was an automatic switch triggered by a content classifier, and that it is a false positive.

Context

The session was routine application development: building an admin access-control / permission-approval feature (role-based access control, an approval workflow, temporary vs. permanent grants, a permission cache, etc.). This is normal authorization-feature engineering — there was no attempt to bypass, circumvent, or abuse anything, and nothing in the conversation violated any safety policy.

Why it looks like a false positive

This kind of work unavoidably uses a lot of access-control domain vocabulary — e.g. permission, authorization, approval, grant, enforce, fallback/bypass, escalation, privileged/"god" account, one-time/temporary permission, policy version. It appears the classifier that decides model routing flagged this benign security-feature discussion as safety-relevant and escalated the model. Permission/auth terminology by itself should not be treated as a risk signal — it's the everyday language of anyone building auth, RBAC, IAM, or admin tooling.

Impact

• Unexpected model changes are surprising: cost, latency, and behavior differ from the model the user explicitly selected.
• Developers working on security/auth/admin tooling will hit this constantly, since the triggering vocabulary is intrinsic to the domain.

Suggestion

Please review/tune the classifier so that legitimate access-control / security-feature development is not misclassified, and so it does not override the user's explicitly configured default model on domain vocabulary alone. Distinguishing "building authorization features" from "attempting to defeat authorization" would lower the false-positive rate here.

Environment

• Claude Code CLI
• Configured default model: Fable 5 (observed switch to Opus mid-session)