refactor(frontend): split SearchaliciousSearchMixin into smaller mixins

[SaitejaKommi]

Summary

This PR addresses technical debt in the frontend search controller by splitting the monolithic SearchaliciousSearchMixin into smaller, logically separated mixins.

The refactor improves separation of concerns by isolating state management, DOM interactions, and API handling, while preserving the existing external behavior and controller composition.

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Related Issue

Fixes #397

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What Changed

Extracted State Management

Created search-ctl-state.ts containing SearchaliciousStateMixin, responsible for:

• @property decorators
• @state decorators
• Internal state coordination
• Preact signal updates

Extracted DOM Interactions

Created search-ctl-dom.ts containing SearchaliciousDomMixin, responsible for:

• Facet element queries
• Chart lookups
• Sort element handling
• DOM-derived search parameter helpers

Extracted API Handling

Created search-ctl-api.ts containing SearchaliciousApiMixin, responsible for:

• search() request flow
• Dynamic parameter construction
• Fetch lifecycle handling
• Response state updates

Recomposed Controller

Updated search-ctl.ts to compose the new mixins in sequence:

SearchaliciousApiMixin(
  SearchaliciousDomMixin(
    SearchaliciousStateMixin(
      SearchaliciousHistoryMixin(
        EventRegistrationMixin(superClass)
      )
    )
  )
)

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Affected Files

• search-ctl.ts
• search-ctl-state.ts
• search-ctl-dom.ts
• search-ctl-api.ts

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Testing

Verification gateway executed successfully:

• Backend unit tests ✅
• Backend integration tests ✅
• Frontend build/tests (dev) ✅
• Frontend build/tests (prod) ✅

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Notes

This is a structural frontend refactor focused on maintainability, readability, and cleaner separation of concerns with no intended runtime behavior changes.