Mechanical --fix output over the newly linted .tsx files (indent,
arrow-parens, comma-dangle, member-delimiter-style, unnecessary type
assertions), plus the three generic-arrow test hooks converted to
function declarations up front: the comma-dangle fixer strips the
<T,> disambiguation comma and turns them into parse errors otherwise.
eslint --fix autofixes plus manual repairs: max-len line splits
(fake-api handlers, notifier/slots JSDoc, spec signatures), charAt over
non-null-asserted indexing in slash detect/menu cores, Array.from for
code-point capping, typeof assertions for unbound-method in specs,
generic getByRole for the send-button cast, effect disposer void-wrap in
command register, and dropped unused type imports.