Audit ui.* VNode factories and harden interactive prop validation

[RtlZeroMemory]

Summary

• audited and tightened ui.* factory behavior across packages/core/src/widgets/ui.ts
• added key-forwarding support for ui.layers, ui.richText, ui.vstack, and ui.hstack
• expanded child filtering to flatten nested children while removing null/false/undefined
• added runtime interactive prop validation for select, slider, checkbox, and radioGroup, and strengthened button.id to non-empty
• integrated new validators into leaf measurement/layout paths to return deterministic ZRUI_INVALID_PROPS fatals instead of downstream crashes
• added three deterministic regression suites:
  • packages/core/src/widgets/__tests__/vnode.factory.test.ts
  • packages/core/src/widgets/__tests__/vnode.children-filter.test.ts
  • packages/core/src/widgets/__tests__/vnode.prop-validation.test.ts
• updated widget docs with factory/validation guarantees and baseline lock metadata

Why

This closes type-safety and runtime-validation gaps in factory construction and interactive widget handling, and adds exhaustive coverage so regressions in factory shape, key forwarding, child normalization, and required-prop enforcement are caught immediately.

Validation

• npm run lint
• npm run build
• npm run typecheck
• node scripts/run-tests.mjs (# tests 2693, # pass 2693, # fail 0)

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Align select measurement fallback with renderer

measureLeaf now uses the raw select.value when no option matches, but the renderer still falls back to the placeholder in that same state (renderToDrawlist/widgets/basic.ts sets label = placeholder when no match is found). When value is non-empty but stale/not present in options (common during async option reloads), measurement can become narrower than rendered text (e.g. value "x" vs rendered " Select… ▼"), which clips the control and destabilizes layout.

Useful? React with 👍 / 👎.

[RtlZeroMemory]

Addressed in ae17eb4.

I aligned measureLeaf select fallback with renderer behavior: when no option matches value, measurement now falls back to placeholder (default "Select…") instead of the raw stale value.

I also added a regression test in packages/core/src/widgets/__tests__/vnode.prop-validation.test.ts (select measurement uses placeholder width when value is stale) to lock this.

Validation rerun:

• npm run lint
• npm run build
• npm run typecheck
• node scripts/run-tests.mjs (pass: 2694, fail: 0)