🐛 fix(channels): resolve TypeScript errors in Channel Hub

Fix all TypeScript compilation errors in packages/gateway/src/channels/hub/:

- crypto/types.ts: Export PrivacyConfig (with CryptoPrivacyConfig alias)
- crypto/node-crypto.ts: Fix X25519 key generation, remove unused imports
- crypto/signal-protocol.ts: Fix generateRandomBytes usage, remove unused imports
- encrypted-adapter.ts: Remove implements clause (can't implement abstract class),
  rename handleIncomingMessage to avoid signature conflict
- universal-adapter.ts: Remove unused imports and disconnectedAt field
- connection-wizard.ts: Fix generateId() call with required prefix
- health-monitor.ts: Remove unused HealthStatus import
- types.ts: Add decryptionError field to StrippedMetadata
- transport/ngrok-provider.ts: Remove unused spawn import
- tunnel-service.ts: Remove unused TunnelConfig import

All packages now build successfully.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: ersinkoc

packages/gateway/src/channels/hub/connection-wizard.ts

@@ -0,0 +1,92 @@
+/**
+ * Signal Protocol E2E Encryption
+ *
+ * End-to-end encryption for Channel Hub using Signal Protocol (Double Ratchet).
+ *
+ * @example
+ * ```typescript
+ * import { createSignalProtocol, EncryptedMessage } from './crypto/index.js';
+ *
+ * // Create protocol instance
+ * const signal = await createSignalProtocol();
+ *
+ * // Initiate session with peer
+ * const peerBundle = await fetchPeerKeyBundle(peerId);
+ * const session = await signal.initiateSession(peerBundle, 'peer-device-123');
+ *
+ * // Encrypt message
+ * const { encrypted } = await signal.encrypt(session.sessionId, 'Hello!');
+ *
+ * // Decrypt message
+ * const { plaintext } = await signal.decrypt(encryptedMessage, 'peer-device-123');
+ * ```
+ */
+
+// Types
+export type {
+  // Core types
+  KeyPair,
+  IdentityKeyPair,
+  PreKey,
+  SignedPreKey,
+  PublicKeyBundle,
+  EncryptedMessage,
+  ChainKey,
+  MessageKey,
+  RootKey,
+  RatchetState,
+  SessionState,
+  SessionInitiation,
+  EncryptionResult,
+  DecryptionResult,
+  KeyStoreConfig,
+  SessionStore,
+  IKeyStore,
+  CryptoProvider,
+  PrivacyConfig,
+} from './types.js';
+
+// Implementations
+export { NodeCryptoProvider, nodeCrypto } from './node-crypto.js';
+export { MemoryKeyStore } from './key-store.js';
+export { SignalProtocol } from './signal-protocol.js';
+
+// Factory function for easy setup
+import { NodeCryptoProvider } from './node-crypto.js';
+import { MemoryKeyStore } from './key-store.js';
+import { SignalProtocol } from './signal-protocol.js';
+
+export interface SignalProtocolSetup {
+  protocol: SignalProtocol;
+  keyStore: MemoryKeyStore;
+  crypto: NodeCryptoProvider;
+}
+
+/**
+ * Create a Signal Protocol instance with default Node.js crypto.
+ * This is the recommended way to initialize the encryption layer.
+ */
+export async function createSignalProtocol(): Promise<SignalProtocolSetup> {
+  const crypto = new NodeCryptoProvider();
+  const keyStore = new MemoryKeyStore(crypto);
+
+  // Initialize with default pre-key count
+  await keyStore.initialize(100);
+
+  const protocol = new SignalProtocol(crypto, keyStore, keyStore);
+
+  return { protocol, keyStore, crypto };
+}
+
+/**
+ * Create Signal Protocol with custom crypto provider.
+ * For advanced use cases or hardware security modules.
+ */
+export async function createSignalProtocolWithProvider(
+  crypto: import('./types.js').CryptoProvider
+): Promise<SignalProtocolSetup> {
+  const keyStore = new MemoryKeyStore(crypto);
+  await keyStore.initialize(100);
+  const protocol = new SignalProtocol(crypto, keyStore, keyStore);
+  return { protocol, keyStore, crypto };
+}