playbooks: add a Haiku 5.5 adaptation chapter when Haiku 5.5 ships #4348

Problem

Haiku 5.5 is expected in the coming weeks. No Haiku family has an adaptation chapter today, so under meta-rule 3 a Haiku session reads no chapter and applies the playbook generically. Haiku 5.5 would be the first Haiku chapter.

Done when

• The Haiku 5.5 prompting guidance is reviewed and a decision is recorded: either a haiku-5-5.md chapter is written, or no chapter is needed and the reason is stated.
• If a chapter is written, it is wired into meta-rule 3, the fable-5 description, and a trigger eval.
• Guidance elsewhere that names Haiku 4.5 as current, including the model-routing text in skills that pick model: haiku, is updated.

Trigger

Haiku 5.5 is released.