Refactor: mark query and handler properties as readonly

[iOvergaard]

Summary

• Mark all @query, @queryAll, and @queryAssignedElements decorated properties as readonly — these are getter-based and never directly assigned
• Mark arrow function handler properties as readonly — these are initialized once and never reassigned
• 25 files changed, 47 substitutions (purely mechanical, no behavioral change)

Test plan

• TypeScript type-check passes with no new errors
• Existing tests still pass (npm run test)

🤖 Generated with Claude Code

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[Copilot]

Pull request overview

This PR is a mechanical TypeScript refactor across Lit-based components to express immutability by marking @query/@queryAll/@queryAssignedElements decorated properties and arrow-function handler properties as readonly.

Changes:

• Mark decorated query properties as readonly across components.
• Mark arrow-function handler properties as readonly where they are intended to be stable references.

Reviewed changes

Copilot reviewed 25 out of 25 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/components/toast-notification/toast-notification.element.ts	Marks @query element reference as readonly.
src/components/toast-notification-container/toast-notification-container.element.ts	Marks internal slot/close handlers as readonly.
src/components/textarea/textarea.element.ts	Marks textarea @query reference as readonly.
src/components/tabs/tab-group.element.ts	Marks queried elements and assigned elements array as readonly.
src/components/table/table-row.element.ts	Marks assigned slot cell nodes as readonly.
src/components/slider/slider.element.ts	Marks queried elements and resize handler as readonly.
src/components/select/select.element.ts	Marks native select @query reference as readonly.
src/components/responsive-container/responsive-container.element.ts	Marks queried elements and assigned elements array as readonly.
src/components/ref-node/ref-node.element.ts	Marks queried element reference as readonly.
src/components/range-slider/range-slider.element.ts	Marks multiple queried element references as readonly.
src/components/radio/radio.element.ts	Marks input @query reference as readonly.
src/components/pagination/pagination.element.ts	Marks queried button list and pages group as readonly.
src/components/modal/modal.element.ts	Marks dialog @query reference as readonly.
src/components/input/input.element.ts	Marks input @query reference as readonly.
src/components/input-file/input-file.element.ts	Marks queried dropzone references as readonly.
src/components/icon-registry/UUIIconRegistry.ts	Marks icon request handler property as readonly.
src/components/file-dropzone/file-dropzone.element.ts	Marks queried input/dropzone references as readonly.
src/components/combobox/combobox.element.ts	Marks queried combobox elements/assigned list as readonly.
src/components/combobox/combobox-async-options-example.ts	Marks async fetch handler as readonly.
src/components/combobox/combobox-async-example.ts	Marks async fetch/search handlers as readonly.
src/components/combobox-list/combobox-list.element.ts	Marks assigned option collections as readonly.
src/components/color-picker/color-picker.element.ts	Marks queried input/preview/swatches as readonly.
src/components/button/button.element.ts	Marks button @query reference as readonly.
src/components/breadcrumbs/breadcrumbs.element.ts	Marks assigned breadcrumb nodes collection as readonly.
src/components/boolean-input/boolean-input.element.ts	Marks input @query reference as readonly.

Comments suppressed due to low confidence (1)

src/components/toast-notification-container/toast-notification-container.element.ts:82

• PR description says arrow-function handler properties are being marked readonly, but in this file pauseAutoClose / resumeAutoClose are still mutable arrow properties. Either mark those as readonly as well (if they’re intended to be stable handler references) or adjust the PR description/scope so it’s clear which handlers are covered.

  private readonly onToastClosed = (e: UUIToastNotificationEvent) => {
    this.removeToast(e.target);

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

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