Where to Buy fragments Saba venues into multiple sections with lowercase headings

[spizeck]

Summary

The production /where-to-buy page currently renders four separate sections that are all on Saba, with headings that lose interior capitalization:

• "Fort bay, saba"
• "Saba"
• "Windwardside / the bottom, saba"
• "Windwardside, saba"

The Island filter dropdown offers the same four near-duplicate options, so a visitor filtering by island sees four confusing choices that all mean Saba.

Evidence

Production HTML today (checked 2026-09-23):

<h2>Fort bay, saba</h2>
<h2>Saba</h2>
<h2>Windwardside / the bottom, saba</h2>
<h2>Windwardside, saba</h2>

and matching <option> values in the Island filter.

Cause in lib/venue-filters.ts:

• islandKey() (lines 73-86) only normalizes Sint Maarten/SXM and Sint Eustatius/Statia variants. Any other locationName lowercases as-is, so "Fort Bay, Saba", "Windwardside, Saba", and "Windwardside / The Bottom, Saba" become three distinct keys instead of one Saba group.
• islandDisplayName() (lines 89-93) capitalizes only the first character of the lowercased key, producing "Fort bay, saba" rather than "Fort Bay, Saba".

Impact

• Headings on a public customer-facing page show incorrect casing.
• Semantically identical locations are split into separate sections, and the "Island" filter granularity is locality-level for Saba while island-level for the other islands — inconsistent with the page's own "Regional Availability" framing (Saba / SXM / Statia).
• Locality detail is not lost by collapsing groups: each VenueCard already renders the raw venue.locationName.

Why existing tests did not catch it

tests/lib/venue-filters.test.ts pins the SXM/Statia normalization and asserts other names "keep ... as lowercase keys" — the current behavior is tested as designed; the Saba-locality case and heading casing were not covered. The where-to-buy fixture data uses uniform location names, so the smoke suite never sees fragmented groups.

Recommended scope

Decide the canonical grouping level, then implement one of:

1. Normalize Saba locality names to the "saba" island key in islandKey() (consistent with the island-level framing; all four current variants collapse into one "Saba" section and one filter option), or
2. Keep locality-level groups but render a properly-cased display name (e.g. preserve the venue's original locationName for the heading instead of the lowercased key), and normalize obvious spelling/formatting variants like "Windwardside / the bottom, saba" vs "Windwardside, saba".

Option 1 matches the existing "island" semantics and the Regional Availability section; note an admin data-entry pass on locationName values may still be worthwhile for consistency on the cards themselves.

Acceptance criteria

• All Saba venues render under one correctly-cased section (or, if locality grouping is kept, headings preserve original casing and spelling variants collapse).
• The Island filter offers one Saba option, not multiple locality strings.
• Venue cards continue to show the raw locationName locality.
• Tests cover Saba-locality normalization and display-name casing.

Overlap

None — #84 (Where to Buy filtering) added the grouping/filtering this builds on; no existing issue tracks the fragmentation.