Auto-mode classifier denial triggers unrequested model fallback (claude-fable-5 → Opus) and accumulates empty orphaned sessions

Environment

• Claude Code desktop app (CCD), macOS (Darwin 25.3.0)
• Selected model: claude-fable-5 (preview)
• Date observed: 2026-07-16 〜 2026-07-17 (JST)

Summary

When the auto-mode classifier denies a Bash action (reason: [Production Deploy] — a wrangler d1 migrations apply --remote), two unexpected side effects occur beyond the denial itself:

1. Unrequested model fallback. The session silently falls back from the user-selected claude-fable-5 to Opus. The user had to re-run /model claude-fable-5 repeatedly (5+ times in one day) because flagged operations kept reverting the session model. The user did not request this fallback and does not want it — from their point of view the flag/fallback pair is a false positive: the specific production operation had already been explicitly approved by the user in-session (via an AskUserQuestion confirmation immediately prior).

1. Empty orphaned sessions accumulate server-side. The claude.ai app's recent-items list filled with ~25 auto-named sessions (pattern: mac-lan-<adjective>-<noun>). Opening them shows they are completely empty. They have no local counterpart: nothing under ~/.claude/projects/** matches, and the session-management API (including archived) does not list them. Timing correlates with the fallback/aborted-start events above, suggesting each aborted/fallback start registers a blank cloud session that never receives content.

Expected

• A classifier denial should deny the action and leave the session as-is — same selected model, no orphan session artifacts.
• If an in-session user approval was just given for exactly this action class, ideally the classifier flow could take that into account (or at least the denial should not cascade into a model switch).

Actual

• Denial → session model switches to Opus until manually reset with /model.
• Repeated empty mac-lan-* sessions pile up in the claude.ai recents list with no way to see what created them.

Repro (as observed)

1. Session on claude-fable-5 with auto mode active.
2. Ask Claude to run a production-deploy-class Bash command (e.g. remote D1 migration).
3. Classifier denies with [Production Deploy].
4. Observe the session model has fallen back to Opus; observe a new empty auto-named session appears in claude.ai recents.

Filed on behalf of the user from the affected session.