Model told more precisely when deferred tools are removed or restored

What

Some tools are made available to the model only partway through a session (deferred tools). Claude Code sends the model an update when that set changes, and this release reworks it:

• The update can now report removedForOtherCause and restoresDeferred. Before, withdrawn tools came only from revoked tools, and removals were not split by cause.
• Tools withdrawn because they were denied can be restored. Each withdrawn tool records whether it goes back to deferred (restoresDeferred), and a restored name also clears its entry for running again.
• Tools marked enableToolsUnlisted are held back from the added lines.
• The deniedLead marker for denied tools used to depend only on the flag tengu_composed_treehouse, whose fallback is false. It is now also set whenever the session's tellsDenies is true, even if the flag is off. How tellsDenies is computed was not traced.

For tengu_composed_treehouse, the flag server returned off for this site's account and for the anonymous baseline, in readings not taken under this release. Nothing has been read about tengu_deferred_tools_pool_change.

Why

This changes what the model is told when tools disappear or are denied. The denial marker may now appear for users who do not have the flag.