Fetch voices from Kokoro API at runtime; replace select with styled voice card grid

scraper/internal/server/server.go

@@ -38,6 +38,10 @@ type Server struct {
 	kokoroURL      string // Kokoro-FastAPI base URL, e.g. http://kokoro:8880
 	kokoroVoice    string // default voice, e.g. af_bella
 
+	// voiceMu guards cachedVoices.
+	voiceMu      sync.RWMutex
+	cachedVoices []string // populated on first request from Kokoro /v1/audio/voices
+
 	// audioMu guards audioCache and audioInFlight.
 	// audioCache maps a cache key to the Kokoro download filename returned by
 	// POST /v1/audio/speech with return_download_link=true.
@@ -62,6 +66,45 @@ func New(addr string, oCfg orchestrator.Config, novel scraper.NovelScraper, log
 	}
 }
 
+// voices returns the list of available Kokoro voices.  On the first call it
+// fetches GET /v1/audio/voices from the Kokoro service and caches the result.
+// If the fetch fails (Kokoro not up yet, network error, etc.) it falls back to
+// the hardcoded kokoroVoices list so the UI is never empty.
+func (s *Server) voices() []string {
+	s.voiceMu.RLock()
+	cached := s.cachedVoices
+	s.voiceMu.RUnlock()
+	if len(cached) > 0 {
+		return cached
+	}
+
+	if s.kokoroURL != "" {
+		ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+		defer cancel()
+		req, err := http.NewRequestWithContext(ctx, http.MethodGet, s.kokoroURL+"/v1/audio/voices", nil)
+		if err == nil {
+			req.Header.Set("Accept", "application/json")
+			resp, err := http.DefaultClient.Do(req)
+			if err == nil {
+				defer resp.Body.Close()
+				var payload struct {
+					Voices []string `json:"voices"`
+				}
+				if resp.StatusCode == http.StatusOK && json.NewDecoder(resp.Body).Decode(&payload) == nil && len(payload.Voices) > 0 {
+					s.voiceMu.Lock()
+					s.cachedVoices = payload.Voices
+					s.voiceMu.Unlock()
+					s.log.Info("fetched kokoro voices", "count", len(payload.Voices))
+					return payload.Voices
+				}
+			}
+		}
+		s.log.Warn("could not fetch kokoro voices, using built-in list")
+	}
+
+	return kokoroVoices
+}
+
 // ListenAndServe starts the HTTP server and blocks until the provided context
 // is cancelled.
 func (s *Server) ListenAndServe(ctx context.Context) error {