#1176 Add a ticketing-preferences hook to the skills that split and create tickets

[williamthorsen]

What

Creates a hook for ticketing preferences that is included into the guidance for planning, creating tickets, and updating tickets after review. Also adds a personal ticketing-preferences rulebook.

Why

Ambient delivery was the only route this policy had, and it fits the policy badly in both directions: every session paid for text most sessions never used, and the sessions that did split work carried it as background rather than at the moment a split is decided or a relationship recorded. Writing the rules into the consuming skills was not an option either, since that imposes one author's ticketing practice on every consumer of the library.

Details

🎉 Features

• williamthorsen-ticketing-preferences is a new rulebook whose whole delivery is hook, carrying the ticket-splitting policy moved out of williamthorsen-workflow-preferences. It joins the williamthorsen collection.
• create-ticket, design-and-plan, and respond-to-review each declare a ticketing-preferences guidance hook, placed at a section boundary ahead of the procedure it governs so no fill reparents the section below it.
• williamthorsen-workflow-preferences keeps the deferral rule, which governs scope in every session rather than ticket creation alone.

🧪 Tests

• guidance-hook-reach.unit.test.ts becomes a HOOK_GUARDS table driving describe.each, so a hook is a row rather than a file of its own. Each of the eight body/hook pairs fails with a message naming both the body and the hook.
• Fills are now built across every hook at once, which puts respond-to-review — the one body declaring two hooks — under an anchor check with both fills spliced, the arrangement sync produces.
• The reviewer-subagent carrier check moves to a describe block of its own, since only implementation-preferences takes that route.

Closes #1176

[github-actions]

Dependency audit

Production dependency audit passed.