fix(wizard): resolve ReScript 12 type errors in Wizard.res + UpdateWizard.res

Wizard.res: seven int-in-template-literal errors (Array.length / count
arithmetic expressions all need ->Int.toString or Int.toString()); four
input_ calls renamed to input (Tea_Html name); all fixes found via
incremental rescript build cycle.

UpdateWizard.res: dict<string, array<string>> → dict<array<string>> —
ReScript 12 dict type takes one type argument (key is always string).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: hyperpolymath