ExitPlanMode fails when plan mode toggled via Shift+Tab after starting with --dangerously-skip-permissions

Bug Description

When starting Claude Code with --dangerously-skip-permissions and then manually toggling into plan mode via Shift+Tab, the ExitPlanMode confirmation flow fails to transition back to act mode. Responding "yes" to the exit plan mode prompt does not actually exit plan mode — the session remains stuck in read-only plan mode.

Steps to Reproduce

1. Start Claude Code with claude --dangerously-skip-permissions
2. Press Shift+Tab to toggle into plan mode
3. Give Claude a task — it creates a plan and calls ExitPlanMode
4. Respond "yes" to confirm exiting plan mode
5. Expected: Claude exits plan mode and begins implementation (act mode with bypass-permissions)
6. Actual: Claude remains in plan mode. System reminders continue showing "Plan mode still active"

Environment

• Claude Code version: 2.1.72
• Terminal: Ghostty (minimal config, window-padding-y = 0,24 only)
• Shell: zsh (macOS Darwin 23.6.0)
• Alias used: claude --dangerously-skip-permissions (via shell alias)
• skipDangerousModePermissionPrompt: true in ~/.claude/settings.json

Notes

• No custom keybindings configured (~/.claude/keybindings.json does not exist)
• No Ghostty input keybindings that could intercept the "yes" response
• The issue appears to be in how Claude Code handles the permission mode state transition when plan mode was entered via Shift+Tab toggle (as opposed to starting with --permission-mode=plan)