Add MIT license header to all source files

[Copilot]

Adds complete MIT license header with copyright notice, permission grant, conditions, and warranty disclaimer to all TypeScript, Vue, and JavaScript source files.

Files updated:

• Components: ActionButton.vue, ActionButton2L.vue, uiKitShared.ts
• Tests: ActionButton.spec.ts, ActionButton2L.spec.ts, index.test.ts
• Configuration: eslint.config.js, vite.config.ts
• Library entry: index.ts

Files that previously had partial 3-line copyright notices were replaced with the full 21-line MIT license text. Configuration and entry files received new headers.

// Copyright (C) 2025 Maxim [maxirmx] Samsonov (www.sw.consulting)
// All rights reserved.
// This file is a part of UI Kit
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions...

Original prompt

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This section details on the original issue you should resolve

<issue_title>Add MIT header</issue_title>
<issue_description>Add MIT header to all files

// Copyright (C) 2025 Maxim [maxirmx] Samsonov (www.sw.consulting)
// All rights reserved.
// This file is a part of UI Kit
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Add MIT header #6

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