dsh-plan-build-toggle

DSH ships plan mode end-to-end, with /plan and /plan off commands, per-session projection, and the exit_plan_mode review all in place. The problem is that the built-in composer control only reveals a "Plan x" chip after plan mode is already on, leaving the input bar with no visible mode entry while in the default Build state. If you prefer keyboard-driven switching and want the mode control always in sight, that hide-then-show interaction feels off.

This plugin drops a persistent Plan｜Build segmented pill into the composer mode-control seat. Clicking Plan executes /plan, clicking Build executes /plan off, exactly as if you had typed them. While the caret sits in the session composer, a bare Tab press toggles between the two; modified-key chords, popups, and other sessions are untouched, and the handler always yields to any earlier listener that consumed the event first. The displayed state is driven by the host projection, not client optimism: switches issued while the agent is running queue as pending and self-correct as projection frames arrive. A bundle patch cleanly takes over the stock ui-plan row, so uninstalling restores the original chip with zero conflicts.

It is built for DSH users who favour the OpenChamber-style always-visible mode toggle and want a fast Tab shortcut to move between "writing code" and "thinking through a plan." It does not alter plan mode semantics (it remains a soft policy prompt, not an enforced sandbox) and does not add new mode vocabulary; it simply turns the mode entry from conditionally appearing to permanently present, making keyboard-first mode switching the default experience.