[Toolkit][Shadcn] Add AlertDialog recipe

[Kocal]

Q	A
Bug fix?	no
New feature?	yes
Docs?	yes
Issues	Fix #...
License	MIT

With this new AlertDialog recipe, the following code:

<twig:AlertDialog>
    <twig:AlertDialog:Trigger>
        <twig:Button {{ ...trigger_attrs }}>Open</twig:Button>
    </twig:AlertDialog:Trigger>
    <twig:AlertDialog:Content>
        <twig:AlertDialog:Header>
            <twig:AlertDialog:Title>Are you absolutely sure?</twig:AlertDialog:Title>
            <twig:AlertDialog:Description>
                This action cannot be undone. This will permanently delete your account
                and remove your data from our servers.
            </twig:AlertDialog:Description>
        </twig:AlertDialog:Header>
        <twig:AlertDialog:Footer>
            <twig:AlertDialog:Cancel>Cancel</twig:AlertDialog:Cancel>
            <twig:AlertDialog:Action>Continue</twig:AlertDialog:Action>
        </twig:AlertDialog:Footer>
    </twig:AlertDialog:Content>
</twig:AlertDialog>

renders:

Enregistrement.de.l.ecran.2025-09-10.a.10.56.33.mov

---

This pull request introduces the new AlertDialog component to the Shadcn UI kit in the Symfony UX Toolkit, including its templates, JavaScript controller, documentation, and manifest. It also updates the toolkit infrastructure to support the new component, refines asset mapping, and improves component context handling. Additionally, some minor documentation and test updates are included.

New AlertDialog Component:

• Added the complete AlertDialog component, including Twig templates for all subcomponents (Content, Header, Footer, Title, Description, Trigger, Action, Cancel), a Stimulus controller for open/close behavior with transitions, and detailed usage examples in EXAMPLES.md. [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11]

• Added a manifest for the AlertDialog component specifying dependencies and recipe details.

Toolkit Infrastructure and Asset Handling:

• Refined the KitContextRunner to better separate Twig and component factory contextualization, improving reliability and maintainability when running code for specific kits. [1] [2]

• Updated asset mapping to expose kit assets under a namespaced path and to exclude kit templates, documentation, and manifests from asset mapping. [1] [2]

• Registered the alert-dialog Stimulus controller in the app's JavaScript entrypoint and importmap, and added the el-transition dependency. [1] [2]

Documentation and Test Updates:

• Updated kit and component documentation to reference the new homepage URL and include AlertDialog in suggestions and tests. [1] [2] [3]

• Minor fix to use self::generateTabs in the toolkit service for consistency.

[Kocal]

Minor refactoring, not really related to this PR

[Kocal]

This data-transition-* syntax from Vue/Alpine.js is do-able thanks to https://github.com/mmccall10/el-transition

FYI it's not possible to use https://stimulus-use.github.io/stimulus-use/#/use-transition because it supports only one target, but we need to transition the overlay and content targets.

[Kocal]

I don't like this schema structure anymore, I will refactor it in another PR