[misc] Move shared components to shared directory (#4286)

Moved the following directories:

```
  - management/client → shared/management/client
  - management/domain → shared/management/domain
  - management/proto → shared/management/proto
  - signal/client → shared/signal/client
  - signal/proto → shared/signal/proto
  - relay/client → shared/relay/client
  - relay/auth → shared/relay/auth
```

and adjusted import paths

shared/relay/auth/hmac/token_test.go

@@ -0,0 +1,105 @@
+package hmac
+
+import (
+	"crypto/sha1"
+	"crypto/sha256"
+	"encoding/base64"
+	"strconv"
+	"testing"
+	"time"
+)
+
+func TestGenerateCredentials(t *testing.T) {
+	secret := "secret"
+	timeToLive := 1 * time.Hour
+	v := NewTimedHMAC(secret, timeToLive)
+
+	creds, err := v.GenerateToken(sha1.New)
+	if err != nil {
+		t.Fatalf("expected no error, got %v", err)
+	}
+
+	if creds.Payload == "" {
+		t.Fatalf("expected non-empty payload")
+	}
+
+	_, err = strconv.ParseInt(creds.Payload, 10, 64)
+	if err != nil {
+		t.Fatalf("expected payload to be a valid unix timestamp, got %v", err)
+	}
+
+	_, err = base64.StdEncoding.DecodeString(creds.Signature)
+	if err != nil {
+		t.Fatalf("expected signature to be base64 encoded, got %v", err)
+	}
+}
+
+func TestValidateCredentials(t *testing.T) {
+	secret := "supersecret"
+	timeToLive := 1 * time.Hour
+	manager := NewTimedHMAC(secret, timeToLive)
+
+	// Test valid token
+	creds, err := manager.GenerateToken(sha1.New)
+	if err != nil {
+		t.Fatalf("expected no error, got %v", err)
+	}
+
+	if err := manager.Validate(sha1.New, *creds); err != nil {
+		t.Fatalf("expected valid token: %s", err)
+	}
+}
+
+func TestInvalidSignature(t *testing.T) {
+	secret := "supersecret"
+	timeToLive := 1 * time.Hour
+	manager := NewTimedHMAC(secret, timeToLive)
+
+	creds, err := manager.GenerateToken(sha256.New)
+	if err != nil {
+		t.Fatalf("expected no error, got %v", err)
+	}
+
+	invalidCreds := &Token{
+		Payload:   creds.Payload,
+		Signature: "invalidsignature",
+	}
+
+	if err = manager.Validate(sha1.New, *invalidCreds); err == nil {
+		t.Fatalf("expected invalid token due to signature mismatch")
+	}
+}
+
+func TestExpired(t *testing.T) {
+	secret := "supersecret"
+	v := NewTimedHMAC(secret, -1*time.Hour)
+	expiredCreds, err := v.GenerateToken(sha256.New)
+	if err != nil {
+		t.Fatalf("expected no error, got %v", err)
+	}
+
+	if err = v.Validate(sha1.New, *expiredCreds); err == nil {
+		t.Fatalf("expected invalid token due to expiration")
+	}
+}
+
+func TestInvalidPayload(t *testing.T) {
+	secret := "supersecret"
+	timeToLive := 1 * time.Hour
+	v := NewTimedHMAC(secret, timeToLive)
+
+	creds, err := v.GenerateToken(sha256.New)
+	if err != nil {
+		t.Fatalf("expected no error, got %v", err)
+	}
+
+	// Test invalid payload
+	invalidPayloadCreds := &Token{
+		Payload:   "invalidtimestamp",
+		Signature: creds.Signature,
+	}
+
+	if err = v.Validate(sha1.New, *invalidPayloadCreds); err == nil {
+		t.Fatalf("expected invalid token due to invalid payload")
+	}
+}