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/static_data_handler.go

@@ -15,12 +15,15 @@ import (
 
 // SeededDataResponse represents the unified seeded data response
 type SeededDataResponse struct {
-	ResidenceTypes        interface{}                            `json:"residence_types"`
-	TaskCategories        interface{}                            `json:"task_categories"`
-	TaskPriorities        interface{}                            `json:"task_priorities"`
-	TaskFrequencies       interface{}                            `json:"task_frequencies"`
-	ContractorSpecialties interface{}                            `json:"contractor_specialties"`
-	TaskTemplates         responses.TaskTemplatesGroupedResponse `json:"task_templates"`
+	ResidenceTypes        interface{}                             `json:"residence_types"`
+	TaskCategories        interface{}                             `json:"task_categories"`
+	TaskPriorities        interface{}                             `json:"task_priorities"`
+	TaskFrequencies       interface{}                             `json:"task_frequencies"`
+	ContractorSpecialties interface{}                             `json:"contractor_specialties"`
+	TaskTemplates         responses.TaskTemplatesGroupedResponse  `json:"task_templates"`
+	HomeProfileOptions    map[string][]services.HomeProfileOption `json:"home_profile_options"`
+	DocumentTypes         []services.HomeProfileOption            `json:"document_types"`
+	DocumentCategories    []services.HomeProfileOption            `json:"document_categories"`
 }
 
 // StaticDataHandler handles static/lookup data endpoints
@@ -54,13 +57,18 @@ func NewStaticDataHandler(
 func (h *StaticDataHandler) GetStaticData(c echo.Context) error {
 	ctx := c.Request().Context()
 
+	// Lookup display labels and home-profile options are localized for the
+	// request's language, so the cache + ETag are keyed by locale.
+	locale := i18n.GetLocale(c)
+	localizer := i18n.GetLocalizer(c)
+
 	// Check If-None-Match header for conditional request
 	// Strip W/ prefix if present (added by reverse proxy, but we store without it)
 	clientETag := strings.TrimPrefix(c.Request().Header.Get("If-None-Match"), "W/")
 
 	// Try to get cached ETag first (fast path for 304 responses)
 	if h.cache != nil && clientETag != "" {
-		cachedETag, err := h.cache.GetSeededDataETag(ctx)
+		cachedETag, err := h.cache.GetSeededDataETag(ctx, locale)
 		if err == nil && cachedETag == clientETag {
 			// Client has the latest data, return 304 Not Modified
 			return c.NoContent(http.StatusNotModified)
@@ -70,10 +78,10 @@ func (h *StaticDataHandler) GetStaticData(c echo.Context) error {
 	// Try to get cached seeded data
 	if h.cache != nil {
 		var cachedData SeededDataResponse
-		err := h.cache.GetCachedSeededData(ctx, &cachedData)
+		err := h.cache.GetCachedSeededData(ctx, locale, &cachedData)
 		if err == nil {
 			// Cache hit - get the ETag and return data
-			etag, etagErr := h.cache.GetSeededDataETag(ctx)
+			etag, etagErr := h.cache.GetSeededDataETag(ctx, locale)
 			if etagErr == nil {
 				c.Response().Header().Set("ETag", etag)
 				c.Response().Header().Set("Cache-Control", "private, max-age=3600")
@@ -116,6 +124,9 @@ func (h *StaticDataHandler) GetStaticData(c echo.Context) error {
 		return err
 	}
 
+	// Localize the lookup display_name fields in place for this request's locale.
+	services.LocalizeLookups(localizer, residenceTypes, taskCategories, taskPriorities, taskFrequencies, contractorSpecialties)
+
 	// Build response
 	seededData := SeededDataResponse{
 		ResidenceTypes:        residenceTypes,
@@ -124,11 +135,14 @@ func (h *StaticDataHandler) GetStaticData(c echo.Context) error {
 		TaskFrequencies:       taskFrequencies,
 		ContractorSpecialties: contractorSpecialties,
 		TaskTemplates:         taskTemplates,
+		HomeProfileOptions:    services.BuildHomeProfileOptions(localizer),
+		DocumentTypes:         services.BuildDocumentTypes(localizer),
+		DocumentCategories:    services.BuildDocumentCategories(localizer),
 	}
 
-	// Cache the data and get ETag
+	// Cache the data and get ETag (per-locale)
 	if h.cache != nil {
-		etag, cacheErr := h.cache.CacheSeededData(ctx, seededData)
+		etag, cacheErr := h.cache.CacheSeededData(ctx, locale, seededData)
 		if cacheErr != nil {
 			log.Warn().Err(cacheErr).Msg("Failed to cache seeded data")
 		} else {