feat: add gateway API, voice service, WebSocket hub, and startup entry

- services/gateway/api: net/http router with JWT auth, stub login, 6 tests
- services/gateway/ws: WebSocket hub with echo support
- services/voice: STT/TTS provider chain with fallback, 6 tests
- cmd/cyrene/main.go: single binary startup, 108 tests total
- Smoke test: health check + login verified on :8080

backend/services/gateway/api/router_test.go

@@ -0,0 +1,136 @@
+package api
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+)
+
+func TestHealth(t *testing.T) {
+	r := New(NewStubAuthManager())
+	srv := httptest.NewServer(r)
+	defer srv.Close()
+
+	resp, err := http.Get(srv.URL + "/api/v1/health")
+	if err != nil {
+		t.Fatalf("GET health: %v", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		t.Errorf("expected 200, got %d", resp.StatusCode)
+	}
+}
+
+func TestLoginAndProtectedEndpoint(t *testing.T) {
+	auth := NewStubAuthManager()
+	r := New(auth)
+	srv := httptest.NewServer(r)
+	defer srv.Close()
+
+	// Login
+	resp, err := http.Post(srv.URL+"/api/v1/auth/login", "application/json",
+		strings.NewReader(`{"username":"admin","password":"admin"}`))
+	if err != nil {
+		t.Fatalf("POST login: %v", err)
+	}
+	resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		t.Errorf("login: expected 200, got %d", resp.StatusCode)
+	}
+
+	// Use token for protected endpoint
+	req, _ := http.NewRequest("GET", srv.URL+"/api/v1/sessions", nil)
+	req.Header.Set("Authorization", "Bearer stub-token-admin")
+	resp2, err := http.DefaultClient.Do(req)
+	if err != nil {
+		t.Fatalf("GET sessions: %v", err)
+	}
+	resp2.Body.Close()
+
+	if resp2.StatusCode != http.StatusOK {
+		t.Errorf("sessions: expected 200, got %d", resp2.StatusCode)
+	}
+}
+
+func TestLoginWrongPassword(t *testing.T) {
+	auth := NewStubAuthManager()
+	r := New(auth)
+	srv := httptest.NewServer(r)
+	defer srv.Close()
+
+	resp, err := http.Post(srv.URL+"/api/v1/auth/login", "application/json",
+		strings.NewReader(`{"username":"admin","password":"wrong"}`))
+	if err != nil {
+		t.Fatalf("POST login: %v", err)
+	}
+	resp.Body.Close()
+
+	if resp.StatusCode != http.StatusUnauthorized {
+		t.Errorf("expected 401, got %d", resp.StatusCode)
+	}
+}
+
+func TestProtectedWithoutToken(t *testing.T) {
+	auth := NewStubAuthManager()
+	r := New(auth)
+	srv := httptest.NewServer(r)
+	defer srv.Close()
+
+	resp, err := http.Get(srv.URL + "/api/v1/sessions")
+	if err != nil {
+		t.Fatalf("GET sessions: %v", err)
+	}
+	resp.Body.Close()
+
+	if resp.StatusCode != http.StatusUnauthorized {
+		t.Errorf("expected 401, got %d", resp.StatusCode)
+	}
+}
+
+func TestStubAuthManager(t *testing.T) {
+	m := NewStubAuthManager()
+
+	// Login as admin
+	token, err := m.Login("admin", "admin")
+	if err != nil {
+		t.Fatalf("Login: %v", err)
+	}
+
+	uid, uname, role, err := m.ValidateToken(token)
+	if err != nil {
+		t.Fatalf("ValidateToken: %v", err)
+	}
+	if uid != "admin" || uname != "admin" || role != "admin" {
+		t.Errorf("wrong claims: %s/%s/%s", uid, uname, role)
+	}
+
+	// Invalid token
+	_, _, _, err = m.ValidateToken("bogus")
+	if err == nil {
+		t.Error("expected error for bogus token")
+	}
+}
+
+func TestCORSHeaders(t *testing.T) {
+	r := New(NewStubAuthManager())
+	srv := httptest.NewServer(r)
+	defer srv.Close()
+
+	req, _ := http.NewRequest("OPTIONS", srv.URL+"/api/v1/health", nil)
+	req.Header.Set("Origin", "http://localhost:5173")
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		t.Fatalf("OPTIONS: %v", err)
+	}
+	resp.Body.Close()
+
+	if resp.StatusCode != http.StatusNoContent {
+		t.Errorf("expected 204 for OPTIONS, got %d", resp.StatusCode)
+	}
+	if resp.Header.Get("Access-Control-Allow-Origin") == "" {
+		t.Error("expected CORS header")
+	}
+}