Shift+Tab mode cycle should skip unavailable modes

Problem

When pressing Shift+Tab to cycle through permission modes (default → plan → auto), all modes are shown including ones unavailable on the user's plan.

On the Max plan, auto mode is not available, but Shift+Tab still cycles to it, showing the error:

Auto mode is unavailable for your plan

This is a poor UX — users shouldn't be presented with modes they can't use.

Expected behavior

Shift+Tab should only cycle through modes that are actually available for the user's current plan. If auto mode is not available, the cycle should be:

default → plan → default

Current behavior

The cycle is always:

default → plan → auto → default

Even when auto mode is unavailable, it appears in the cycle and shows an error message.

Environment

• Claude Code CLI
• Max plan (individual)