v2.4.3: toolkit-driven kit options form

The kit options form is now driven by the toolkit itself

Send a kit and the toolkit shows the options form, collects your answers,
slices, and brings back the readiness card as one smooth step. The model no
longer has to ask for the form itself, so the small local models this runs on
can no longer stall a job by garbling that request. Your plate previews, a
fresh bed photo, the review document, and the final bed-clear approval all
arrive the same as before, and the safety gate is untouched.

Also in this release

• A mistyped kit filename recovers itself. If the model retypes an uploaded
  file's name and mangles it, the toolkit finds the real file by its stable id
  instead of giving up.
• The first taps on a fresh form register. A very fast first tap used to
  flash without checking the box; those early taps now land.

Validated end to end on real hardware (Snapmaker U1, gemma4 over Ollama) with
the full test suite passing (1002 tests).