Address remaining React hooks lint warnings in LiveProvider and Editor

[ryan-roemer]

Five oxlint warnings remain, set to warn in .oxlintrc.json.

LiveProvider effect deps

useEffect(() => {
  transpileAsync(code).catch(onError);
}, [code, scope, noInline, transformCode]);

Do not apply the suggested fix as-is. The linter calls scope, noInline, and transformCode unnecessary because they are not in the effect body. They are used by transpileAsync, which closes over them. Removing them stops re-transpiling when scope or transformCode changes.

Real bug the linter misses: transpileAsync also closes over enableTypeScript, which is not in the deps, so toggling it at runtime does not re-transpile.

Fix: make transpileAsync a useCallback with deps scope, noInline, transformCode, enableTypeScript, and depend on it. Changes when transpilation runs, notably for an inline scope={{ ... }}.

jsx-no-constructed-context-values

New context object every render re-renders all consumers. Needs useCallback on onError/onChange as well as useMemo, and onChange depends on transpileAsync — so entangled with the above.

set-state-in-effect in Editor

useEffect(() => setCode(props.code), [props.code]) syncs state from props. Both standard fixes change the controlled/uncontrolled contract of a contentEditable editor.

Order

1. Add tests that changing scope, noInline, transformCode, and enableTypeScript re-transpiles. Only code is covered today. The enableTypeScript one should fail, confirming the bug above.
2. Fix the stale closure.
3. useCallback/useMemo refactor.
4. Editor prop sync, separately.

Worth holding until #415 is understood.