- Use existing MULTIPLIER_S/M/L from \$entities/Font in SliderArea instead
of inlining the 0.5/0.75/1 literals (constants already existed but were
duplicated at the call site).
- Centralize API base URL in \$shared/api/endpoints.ts (was duplicated
between proxyFonts and FilterAndSortFonts filters api).
- Promote every 'glyphdiff:...' localStorage key to a named module-level
STORAGE_KEY constant. Test files now import the source constant rather
than redeclaring it (eliminates silent-typo divergence risk).
- queryKeys: add mutation-safety test for batch(), key hierarchy tests
(list/batch/detail keys rooted in their parent base keys), and
unique-key test for different detail IDs
- BaseQueryStore: add initial-state test (data undefined, isError false
before any fetch resolves)
- BatchFontStore: add FontResponseError type assertion on malformed
response, null error assertion on success, and setIds([]) disables
query and returns empty fonts without triggering a fetch
Ilia Mashkov