i18n: backend-localized lookups, suggestions, and static data (10 languages)

- suggestion_service: fix scorer (stringList unmarshal accepts scalar|array;
  anchor scoring on base universal score so bool matches no longer tie); add
  localizeReasons for human-readable, Accept-Language-localized match reasons
- lookup_i18n: localize lookup display names, home-profile options, document
  types/categories via internal/i18n
- static_data_handler: per-locale seeded-data response (display_name, home
  profile options, document types/categories) with per-locale cache + ETag
- settings_handler: invalidate per-locale seeded-data cache on lookup change
  instead of pre-warming a single non-localized blob
- cache_service: per-locale seeded-data keys + ETag
- DTOs: add DisplayName fields (task/residence/contractor)
- translations: add suggestion.reason.* and lookup.* keys across all 10 langs
- cmd/api: extract startup helpers + tests

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

internal/handlers/suggestion_handler.go

@@ -7,6 +7,7 @@ import (
 	"github.com/labstack/echo/v4"
 
 	"github.com/treytartt/honeydue-api/internal/apperrors"
+	"github.com/treytartt/honeydue-api/internal/i18n"
 	"github.com/treytartt/honeydue-api/internal/middleware"
 	"github.com/treytartt/honeydue-api/internal/services"
 )
@@ -41,7 +42,7 @@ func (h *SuggestionHandler) GetSuggestions(c echo.Context) error {
 		return apperrors.BadRequest("error.invalid_id")
 	}
 
-	resp, err := h.suggestionService.GetSuggestions(uint(residenceID), user.ID)
+	resp, err := h.suggestionService.GetSuggestions(uint(residenceID), user.ID, i18n.GetLocalizer(c))
 	if err != nil {
 		return err
 	}