Unify list-view conditional features (conditional formatting / row-action visibility) onto the CEL engine

[xuyushun441-sys]

Context

B2 standardized field conditional rules on CEL (@objectstack/formula), evaluated identically client + server. But the list view still uses older, bespoke JSON condition shapes for:

• conditional formatting (evaluateConditionalFormatting in packages/plugin-list/src/ListView.tsx),
• row-level action visibility,
• (and the legacy form condition: {field, equals/in} path in the form renderer).

Goal

Converge these onto the same CEL engine + evalFieldPredicate helper so the whole platform speaks one expression dialect, and authors can reuse the same record.* predicates everywhere.

Scope

• objectui: packages/plugin-list (conditional formatting + row-action visibleWhen), and optionally retire/forward the legacy condition JSON in packages/components/src/renderers/form/form.tsx to CEL (with back-compat).
• No framework change required (client-side rendering concern), unless we also want server-side list policy.

Acceptance

• A list view can express conditional formatting + row-action visibility as CEL predicates over the row record.
• Legacy JSON condition keeps working (back-compat) or is transparently translated.
• Unit tests + a live e2e on a showcase list.
• Docs/skill note (objectstack-ui) updated.

Priority

Lower than #1581 (parent-scoped grid lock) and #1582 (Studio CEL editor) — do those first.