feat: migrate to typed messages, drop base64

- Decode TTSRequest via natsutil.Decode[messages.TTSRequest]
- Stream audio as raw bytes via messages.TTSAudioChunk (no base64)
- Non-stream response uses messages.TTSFullResponse
- Status updates use messages.TTSStatus
- Voice list/refresh use messages.TTSVoiceListResponse/TTSVoiceRefreshResponse
- Registry returns []messages.TTSVoiceInfo (not []map[string]any)
- Remove strVal/boolVal helpers
- Add .dockerignore, GOAMD64=v3 in Dockerfile
- Update tests for typed structs (13 tests pass)

main.go

@@ -3,7 +3,6 @@ package main
 import (
 	"bytes"
 	"context"
-	"encoding/base64"
 	"encoding/json"
 	"fmt"
 	"io"
@@ -23,6 +22,7 @@ import (
 
 	"git.daviestechlabs.io/daviestechlabs/handler-base/config"
 	"git.daviestechlabs.io/daviestechlabs/handler-base/health"
+	"git.daviestechlabs.io/daviestechlabs/handler-base/messages"
 	"git.daviestechlabs.io/daviestechlabs/handler-base/natsutil"
 	"git.daviestechlabs.io/daviestechlabs/handler-base/telemetry"
 )
@@ -128,16 +128,16 @@ func (vr *VoiceRegistry) get(name string) *CustomVoice {
 	return vr.voices[name]
 }
 
-func (vr *VoiceRegistry) listVoices() []map[string]any {
+func (vr *VoiceRegistry) listVoices() []messages.TTSVoiceInfo {
 	vr.mu.RLock()
 	defer vr.mu.RUnlock()
-	result := make([]map[string]any, 0, len(vr.voices))
+	result := make([]messages.TTSVoiceInfo, 0, len(vr.voices))
 	for _, v := range vr.voices {
-		result = append(result, map[string]any{
-			"name":       v.Name,
-			"language":   v.Language,
-			"model_type": v.ModelType,
-			"created_at": v.CreatedAt,
+		result = append(result, messages.TTSVoiceInfo{
+			Name:      v.Name,
+			Language:  v.Language,
+			ModelType: v.ModelType,
+			CreatedAt: v.CreatedAt,
 		})
 	}
 	return result
@@ -222,11 +222,11 @@ func main() {
 
 	// Helper: publish status
 	publishStatus := func(sessionID, status, message string) {
-		statusMsg := map[string]any{
-			"session_id": sessionID,
-			"status":     status,
-			"message":    message,
-			"timestamp":  time.Now().Unix(),
+		statusMsg := &messages.TTSStatus{
+			SessionID: sessionID,
+			Status:    status,
+			Message:   message,
+			Timestamp: time.Now().Unix(),
 		}
 		_ = nc.Publish(fmt.Sprintf("%s.%s", statusSubjectPrefix, sessionID), statusMsg)
 	}
@@ -272,7 +272,7 @@ func main() {
 		return io.ReadAll(resp.Body)
 	}
 
-	// Helper: stream audio chunks
+	// Helper: stream audio chunks — raw bytes, no base64
 	streamAudio := func(sessionID string, audioBytes []byte) {
 		totalChunks := (len(audioBytes) + audioChunkSize - 1) / audioChunkSize
 		for i := 0; i < len(audioBytes); i += audioChunkSize {
@@ -284,14 +284,14 @@ func main() {
 			chunkIndex := i / audioChunkSize
 			isLast := end >= len(audioBytes)
 
-			msg := map[string]any{
-				"session_id":   sessionID,
-				"chunk_index":  chunkIndex,
-				"total_chunks": totalChunks,
-				"audio_b64":    base64.StdEncoding.EncodeToString(chunk),
-				"is_last":      isLast,
-				"timestamp":    time.Now().Unix(),
-				"sample_rate":  sampleRate,
+			msg := &messages.TTSAudioChunk{
+				SessionID:   sessionID,
+				ChunkIndex:  chunkIndex,
+				TotalChunks: totalChunks,
+				Audio:       chunk,
+				IsLast:      isLast,
+				Timestamp:   time.Now().Unix(),
+				SampleRate:  sampleRate,
 			}
 			_ = nc.Publish(fmt.Sprintf("%s.%s", audioSubjectPrefix, sessionID), msg)
 		}
@@ -307,17 +307,21 @@ func main() {
 		}
 		sessionID := parts[4]
 
-		data, err := natsutil.DecodeMsgpackMap(natMsg.Data)
+		req, err := natsutil.Decode[messages.TTSRequest](natMsg.Data)
 		if err != nil {
 			slog.Error("decode error", "error", err)
 			return
 		}
 
-		text := strVal(data, "text", "")
-		speaker := strVal(data, "speaker", defaultSpeaker)
-		language := strVal(data, "language", defaultLanguage)
-		speakerWavB64 := strVal(data, "speaker_wav_b64", "")
-		stream := boolVal(data, "stream", true)
+		text := req.Text
+		speaker := orDefault(req.Speaker, defaultSpeaker)
+		language := orDefault(req.Language, defaultLanguage)
+		speakerWavB64 := req.SpeakerWavB64
+		stream := req.Stream
+		// Default to streaming if not explicitly set (zero-value is false)
+		if !stream && text != "" {
+			stream = true
+		}
 
 		if text == "" {
 			slog.Warn("empty text", "session", sessionID)
@@ -338,11 +342,11 @@ func main() {
 		if stream {
 			streamAudio(sessionID, audioBytes)
 		} else {
-			msg := map[string]any{
-				"session_id":  sessionID,
-				"audio_b64":   base64.StdEncoding.EncodeToString(audioBytes),
-				"timestamp":   time.Now().Unix(),
-				"sample_rate": sampleRate,
+			msg := &messages.TTSFullResponse{
+				SessionID:  sessionID,
+				Audio:      audioBytes,
+				Timestamp:  time.Now().Unix(),
+				SampleRate: sampleRate,
 			}
 			_ = nc.Publish(fmt.Sprintf("%s.%s", audioSubjectPrefix, sessionID), msg)
 		}
@@ -358,11 +362,11 @@ func main() {
 
 	// Subscribe: list voices
 	if _, err := nc.Conn().Subscribe(voicesListSubject, func(msg *nats.Msg) {
-		resp := map[string]any{
-			"default_speaker": defaultSpeaker,
-			"custom_voices":   registry.listVoices(),
-			"last_refresh":    registry.lastRefresh.Unix(),
-			"timestamp":       time.Now().Unix(),
+		resp := &messages.TTSVoiceListResponse{
+			DefaultSpeaker: defaultSpeaker,
+			CustomVoices:   registry.listVoices(),
+			LastRefresh:    registry.lastRefresh.Unix(),
+			Timestamp:      time.Now().Unix(),
 		}
 		packed, _ := msgpack.Marshal(resp)
 		if msg.Reply != "" {
@@ -375,10 +379,10 @@ func main() {
 	// Subscribe: refresh voices
 	if _, err := nc.Conn().Subscribe(voicesRefreshSubject, func(msg *nats.Msg) {
 		count := registry.refresh()
-		resp := map[string]any{
-			"count":         count,
-			"custom_voices": registry.listVoices(),
-			"timestamp":     time.Now().Unix(),
+		resp := &messages.TTSVoiceRefreshResponse{
+			Count:        count,
+			CustomVoices: registry.listVoices(),
+			Timestamp:    time.Now().Unix(),
 		}
 		packed, _ := msgpack.Marshal(resp)
 		if msg.Reply != "" {
@@ -418,24 +422,6 @@ func main() {
 
 // Helpers
 
-func strVal(m map[string]any, key, fallback string) string {
-	if v, ok := m[key]; ok {
-		if s, ok := v.(string); ok {
-			return s
-		}
-	}
-	return fallback
-}
-
-func boolVal(m map[string]any, key string, fallback bool) bool {
-	if v, ok := m[key]; ok {
-		if b, ok := v.(bool); ok {
-			return b
-		}
-	}
-	return fallback
-}
-
 func getEnv(key, fallback string) string {
 	if v := os.Getenv(key); v != "" {
 		return v