Feat/filter list display

[kevinmdd]

Fixes #671

Summary: Replaced dropdown/button displays for enum filters with a new Filter List display mode that shows options as a compact vertical list, showing the first 4 with an "Expand All" toggle when there are 5 or more.

• User experience
  • Enum filters (Language Authority, Modality, Languoid Type, Territory Type, ISO Language Status) now show as a vertical plain-text list instead of a dropdown or button group
  • Options are visible at a glance without needing to open a dropdown
  • Increased font bold size and spacing between labels for better visibility
  • "Expand All" / "Collapse" button appears when there are more than 4 options
• Logical changes
  • Added FilterList to the SelectorDisplay enum
  • Selector now slices visible options to the first 4 when in FilterList mode and not expanded
  • FilterListMoreButton component added to Selector for the expand/collapse toggle
  • SelectorContainer renders as flex-column with full width for FilterList
  • useClickOutside guarded to not collapse FilterList state on outside click
• Data
  • No data changes
• Refactors
  • LanguageModalitySelector, LanguageScopeSelector, TerritoryScopeSelector, VitalitySelector updated to accept and forward a display prop
  • VitalitySelector.test updated to include FilterList in the SelectorDisplay mock and added "Expand All" click before checking all options are visible
  • Continued Refactors for: selectorbuttons, filterlist, and selectoroptions in controls.css

Out of scope/Future work: The dual meaning of expanded state (dropdown open vs filter list expanded) could be split into two separate state variables for clarity.

Test Plan and Screenshots

How to test the changes in this PR: Run npm run dev, open the Filter panel, then verify enum filters show as vertical lists and "Expand All" works.

Before	After

Checklist

Feel free to check off or just delete items in this section as you have completed them.

Summary

• Clear description of what and why
• Scope kept focused; note follow-ups if any
• Set yourself as assignee
• Mention the issue (usually by writing "Fixes #ISSUE_NUMBER" or "Closes #ISSUE_NUMBER")

Testing

• npm run lint
• npm run build
• npm run test
• Tests added or updated for changed logic
• npm run dev -- tried out the website directly
• Include screenshots as noted below
• Write comments on manual testing

Changes

Visual changes

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Data changes

• TSV, SVG, etc. edits in public/data/
• Corresponding readmes updated in public/data/
• Load/connect/compute updates in src/features/data/ including how we aggregate data or compute derived values

Internal changes

• Logical changes
• Refactors, moving files around
• If you notice any changes that require explanations, make sure to include the explanations in the code as well.

Docs

• Code is self-documenting, or if not, comments are added where needed.
• Updated markdown readme files documenting how the code behaves or how to develop in case there are any relevant changes to make.

[github-actions]

Cloudflare Pages preview

• Deploy URL: https://f9939cf6.lang-nav.pages.dev/lang-nav/
• Branch alias: https://pr-686.lang-nav.pages.dev/lang-nav/
  Commit: 3816391