feat: rewrite tts-module in Go

Replace Python streaming TTS service with Go for smaller container images.
- VoiceRegistry: discovers custom voices from model store
- NATS subscriptions: TTS requests, voice list, voice refresh
- JetStream AI_VOICE_TTS stream setup
- Chunked audio streaming over NATS
- Dockerfile: multi-stage golang:1.25-alpine → scratch
- CI: Gitea Actions with lint/test/release/docker/notify

main_test.go

@@ -0,0 +1,147 @@
+package main
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestVoiceRegistryRefresh(t *testing.T) {
+	dir := t.TempDir()
+
+	// Create a voice directory
+	voiceDir := filepath.Join(dir, "test-voice")
+	os.MkdirAll(voiceDir, 0o755)
+	info := map[string]string{"name": "test-voice", "language": "en", "type": "coqui-tts", "created_at": "2024-01-01"}
+	infoData, _ := json.Marshal(info)
+	os.WriteFile(filepath.Join(voiceDir, "model_info.json"), infoData, 0o644)
+	os.WriteFile(filepath.Join(voiceDir, "model.pth"), []byte("fake"), 0o644)
+
+	vr := newVoiceRegistry(dir)
+	count := vr.refresh()
+	if count != 1 {
+		t.Errorf("refresh() = %d, want 1", count)
+	}
+
+	voice := vr.get("test-voice")
+	if voice == nil {
+		t.Fatal("expected voice 'test-voice'")
+	}
+	if voice.Language != "en" {
+		t.Errorf("language = %q, want %q", voice.Language, "en")
+	}
+	if voice.ModelPath != filepath.Join(voiceDir, "model.pth") {
+		t.Errorf("model_path = %q", voice.ModelPath)
+	}
+
+	voices := vr.listVoices()
+	if len(voices) != 1 {
+		t.Errorf("listVoices() len = %d, want 1", len(voices))
+	}
+}
+
+func TestVoiceRegistryMissing(t *testing.T) {
+	vr := newVoiceRegistry("/nonexistent/path")
+	count := vr.refresh()
+	if count != 0 {
+		t.Errorf("refresh() = %d, want 0", count)
+	}
+}
+
+func TestVoiceRegistryNoModel(t *testing.T) {
+	dir := t.TempDir()
+	voiceDir := filepath.Join(dir, "bad-voice")
+	os.MkdirAll(voiceDir, 0o755)
+	info := map[string]string{"name": "bad-voice"}
+	infoData, _ := json.Marshal(info)
+	os.WriteFile(filepath.Join(voiceDir, "model_info.json"), infoData, 0o644)
+	// No model.pth
+
+	vr := newVoiceRegistry(dir)
+	count := vr.refresh()
+	if count != 0 {
+		t.Errorf("refresh() = %d, want 0", count)
+	}
+}
+
+func TestSynthesizeHTTP(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/v1/audio/speech" {
+			t.Errorf("unexpected path: %s", r.URL.Path)
+		}
+		if r.Method != http.MethodPost {
+			t.Errorf("expected POST, got %s", r.Method)
+		}
+
+		var payload map[string]any
+		json.NewDecoder(r.Body).Decode(&payload)
+		if payload["text"] != "hello" {
+			t.Errorf("unexpected text: %v", payload["text"])
+		}
+
+		w.Write([]byte{0x01, 0x02, 0x03, 0x04})
+	}))
+	defer ts.Close()
+
+	// Test the XTTS synthesis HTTP call directly
+	client := ts.Client()
+	body := `{"text":"hello","speaker":"default","language":"en"}`
+	resp, err := client.Post(ts.URL+"/v1/audio/speech", "application/json", strings.NewReader(body))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != 200 {
+		t.Errorf("status = %d, want 200", resp.StatusCode)
+	}
+}
+
+func TestHelperFunctions(t *testing.T) {
+	m := map[string]any{"text": "hello", "stream": true, "count": 42}
+
+	if got := strVal(m, "text", ""); got != "hello" {
+		t.Errorf("strVal(text) = %q", got)
+	}
+	if got := strVal(m, "missing", "def"); got != "def" {
+		t.Errorf("strVal(missing) = %q", got)
+	}
+	if got := boolVal(m, "stream", false); !got {
+		t.Errorf("boolVal(stream) = %v", got)
+	}
+	if got := boolVal(m, "missing", true); !got {
+		t.Errorf("boolVal(missing) = %v", got)
+	}
+}
+
+func TestGetEnv(t *testing.T) {
+	t.Setenv("MY_TEST_VAR", "value")
+	if got := getEnv("MY_TEST_VAR", "fallback"); got != "value" {
+		t.Errorf("getEnv = %q", got)
+	}
+	if got := getEnv("NONEXISTENT_XYZ", "fallback"); got != "fallback" {
+		t.Errorf("getEnv = %q", got)
+	}
+}
+
+func TestGetEnvInt(t *testing.T) {
+	t.Setenv("MY_PORT", "8080")
+	if got := getEnvInt("MY_PORT", 3000); got != 8080 {
+		t.Errorf("getEnvInt = %d", got)
+	}
+	if got := getEnvInt("NONEXISTENT_XYZ", 3000); got != 3000 {
+		t.Errorf("getEnvInt = %d", got)
+	}
+}
+
+func TestOrDefault(t *testing.T) {
+	if got := orDefault("", "en"); got != "en" {
+		t.Errorf("orDefault('', 'en') = %q", got)
+	}
+	if got := orDefault("fr", "en"); got != "fr" {
+		t.Errorf("orDefault('fr', 'en') = %q", got)
+	}
+}