fix(menu): sync trigger aria-disabled and tabindex on LiveView patch

[karim-semmoud]

Summary

Fixes the follow-up to #61 where toggling <.menu disabled={...}> correctly patched native disabled on the trigger, but aria-disabled and tabindex stayed frozen at their initial SSR values. That broke keyboard navigation when enabling a bulk-actions menu after row selection.
Root cause: aria-disabled and tabindex remain in Trigger.ignored_attrs, so LiveView does not patch them. Hook updated() already calls menu.render(), but Zag's getTriggerProps() does not emit those attrs, and spreadProps only toggled native disabled.
This change derives aria-disabled and tabindex from the patched native disabled attribute during client render(), matching Connect.trigger/1.

Will close #59

Changes

• assets/components/menu.ts: add triggerDisabledAttrs/1 and spread aria-disabled + tabindex on the root trigger in render()
• assets/test/component/menu.test.ts: cover enable/disable toggle updating a11y attrs
• e2e/test/components/menu_test.exs: playground disabled switch toggles trigger a11y state
• e2e/test/support/models/menu_model.ex: helpers for trigger enabled/disabled assertions
• priv/static/menu.mjs: rebuilt bundle

Test plan

• pnpm test -- assets/test/component/menu.test.ts
• mix assets.build
• cd e2e && mix test test/components/menu_test.exs:82