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>

cmd/api/startup.go

@@ -0,0 +1,32 @@
+package main
+
+import "time"
+
+// shouldInitEmail returns true if email config has host and user set.
+func shouldInitEmail(host, user string) bool {
+	return host != "" && user != ""
+}
+
+// shouldInitStorage returns true if upload directory is configured.
+func shouldInitStorage(uploadDir string) bool {
+	return uploadDir != ""
+}
+
+// shouldInitEncryption returns true if encryption key is set.
+func shouldInitEncryption(encryptionKey string) bool {
+	return encryptionKey != ""
+}
+
+// connectWithRetry attempts a connection with exponential backoff.
+// Returns nil on success or the last error after all retries fail.
+func connectWithRetry(connect func() error, maxRetries int) error {
+	var err error
+	for i := 0; i < maxRetries; i++ {
+		err = connect()
+		if err == nil {
+			return nil
+		}
+		time.Sleep(time.Duration(i+1) * time.Millisecond) // use ms in tests
+	}
+	return err
+}