Add support for Haiku 5.5 'xhigh' & 'max', please

Currently, only Instant, Low, Medium, and High are supported for Claude Haiku 5.5 from the dropdown.

But benchmarks for Claude Haiku 5.5 on "Xhigh" and "Max" look tasty, "Max" looks better or on par with Gemini 3.8 Flash with "High" (which is the max available option).

So switching from Gemini 3.8 Flash to Claude Haiku 5.5 might be an obvious strong money save if all the reasoning options become available (and as long as the context window is <100K, because for context >100K with Haiku 5.5 they bill 5x per i/o token, $0.50/$2.50, which is something you might wanna add to the model info popup btw).