Deactivate menu and clear pending match on disconnect

[feritcemkahraman]

Summary

• Clear this.match and call this.deactivate() inside TextExpander#destroy() so disconnecting <text-expander> tears down an open menu, resets combobox ARIA attributes, and ignores late async text-expander-change provider resolutions from the destroyed state.
• Delete the states entry before calling state.destroy() in disconnectedCallback() so a text-expander-deactivate listener that synchronously reconnects <text-expander> does not have its newly created connectedCallback() state deleted afterward.

Testing

• npx eslint .
• npx tsc && npx rollup -c && npx rollup -c rollup.config.test.js
• npx karma start test/karma.config.cjs (Chromium Headless: 47 passed)
• Note: Firefox / WebKit browser matrices were not run locally.

[Copilot]

🟡 Changes recommended

Disconnect cleanup remains unsafe during synchronous event callbacks.

3 open issues

• Guard activation when listener removes the element · New
• Prevent reentrant teardown during deactivation listeners · New
• Detach handlers before synchronous deactivation listeners run · New

What changed in this PR

Improves <text-expander> disconnect cleanup and preserves replacement state during reconnection.

Changes:

• Clear pending matches and deactivate open menus during teardown.
• Delete disconnected state before cleanup callbacks run.
• Add disconnect, reconnection, and delayed-provider regression tests.

File	Description
test/​text-expander-element-test.js	Adds lifecycle cleanup regression tests.
src/​text-expander-element.ts	Updates teardown and state-deletion order.

_{Review effort: Max}