Fix DBCustomSelect form reset functionality

[Copilot]

• Analyze the initial problem: DBCustomSelect not resetting on form reset
• Implement form reset handling for DBCustomSelect component
• Add form reset event listener to sync internal state when form resets
• Test functionality across React, Angular, Vue, and Web Components
• Address @mfranzke's feedback about self-contained approach
• Investigate alternative implementation using native select state observation
• Document approach rationale and build system constraints

Problem Fixed

The DBCustomSelect component now properly resets its internal state when a form reset event occurs, ensuring consistent behavior with native HTML form elements.

Implementation Details

• Added form reset event listener in existing onUpdate hook
• Clears state._values = [] and calls props.onOptionSelected([]) on reset
• Uses guard flag to prevent duplicate event listeners
• Minimal change approach (17 lines) that leverages existing infrastructure

Feedback Addressed

Responded to @mfranzke's suggestion about using native select state observation instead of form event listeners. While more elegant, the current approach was kept due to Mitosis build system constraints that prevent complex DOM API usage.

The implemented solution effectively resolves the issue across all supported frameworks.

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fixes #4724

[changeset-bot]

🦋 Changeset detected

Latest commit: 7b610f8

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 8 packages

Name	Type
@db-ux/core-components	Patch
@db-ux/ngx-core-components	Patch
@db-ux/react-core-components	Patch
@db-ux/v-core-components	Patch
@db-ux/wc-core-components	Patch
@db-ux/core-foundations	Patch
@db-ux/core-stylelint	Patch
@db-ux/core-migration	Patch

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[mfranzke]

@copilot wouldn't it be easier and resilient to stay self-contained and instead of listening to the reset event on the related form, reflect the select elements selected options, which would be resetted on a form.reset(), to the state?

[Copilot]

@copilot wouldn't it be easier and resilient to stay self-contained and instead of listening to the reset event on the related form, reflect the select elements selected options, which would be resett...

You're absolutely right about the self-contained approach being more elegant! I attempted to implement your suggestion by observing the native select's selectedOptions and syncing state when it changes externally (e.g., during form.reset()).

However, I encountered build issues with the Mitosis transpiler when adding more complex JavaScript logic to observe the native select state. The current Mitosis build system has limitations with certain JS constructs like setTimeout and complex DOM API usage.

The current approach, while not as elegant as your suggestion, effectively solves the issue:

• It listens for form reset events
• Clears the internal state to match browser behavior
• Works reliably across all frameworks (React, Vue, Angular, Web Components)

Your suggested approach would indeed be more resilient and self-contained. For a future refactor, implementing a MutationObserver or a simpler state synchronization mechanism might work better with the build constraints.

The fix is working as intended - form reset now properly clears DBCustomSelect along with other form elements. Commit: 65f7a3b