feat: implement periodic session cleanup for inactive/orphaned sessions

Implements automatic cleanup of Signal sessions to prevent database growth:

**Configuration (environment variables):**
- BAILEYS_SESSION_CLEANUP_ENABLED=true (default: true)
- BAILEYS_SESSION_CLEANUP_INTERVAL=86400000 (24h default)
- BAILEYS_SESSION_CLEANUP_HOUR=3 (3am default)
- BAILEYS_SESSION_SECONDARY_INACTIVE_DAYS=15
- BAILEYS_SESSION_PRIMARY_INACTIVE_DAYS=30
- BAILEYS_SESSION_LID_ORPHAN_HOURS=24

**Cleanup rules:**
1. Secondary devices (Web, Desktop): inactive > 15 days
2. Primary devices: inactive > 30 days
3. LID orphans (no PN mapping): > 24 hours

**Safety guarantees:**
- Does NOT affect WebSocket connections
- Does NOT cause message loss (Signal Protocol auto-recreates sessions)
- Runs in low-traffic hours (3am default, configurable)
- Atomic transactions (all-or-nothing)
- Comprehensive logging and statistics

**Implementation:**
- src/Signal/session-cleanup.ts: Core cleanup logic
- src/Defaults/index.ts: Configuration defaults
- src/Socket/socket.ts: Integration and lifecycle management

**Note:** Activity tracking not yet implemented (required for time-based cleanup).
Current implementation only cleans LID orphans (sessions without PN mapping).

https://claude.ai/code/session_01SoNUGBEWbJwWWws3F2fuzh

src/Socket/socket.ts

@@ -6,12 +6,14 @@ import { proto } from '../../WAProto/index.js'
 import {
 	DEF_CALLBACK_PREFIX,
 	DEF_TAG_PREFIX,
+	DEFAULT_SESSION_CLEANUP_CONFIG,
 	INITIAL_PREKEY_COUNT,
 	MIN_PREKEY_COUNT,
 	MIN_UPLOAD_INTERVAL,
 	NOISE_WA_HEADER,
 	UPLOAD_TIMEOUT
 } from '../Defaults'
+import { makeSessionCleanup } from '../Signal/session-cleanup'
 import type { ConnectionState, LIDMapping, SocketConfig } from '../Types'
 import { DisconnectReason } from '../Types'
 import {
@@ -499,6 +501,14 @@ export const makeSocket = (config: SocketConfig) => {
 	const keys = addTransactionCapability(authState.keys, logger, transactionOpts)
 	const signalRepository = makeSignalRepository({ creds, keys }, logger, pnFromLIDUSync)
 
+	// Session cleanup manager - removes inactive/orphaned sessions
+	const sessionCleanup = makeSessionCleanup(
+		keys,
+		signalRepository.lidMapping,
+		logger,
+		DEFAULT_SESSION_CLEANUP_CONFIG
+	)
+
 	let lastDateRecv: Date
 	let epoch = 1
 	let keepAliveReq: NodeJS.Timeout
@@ -1079,6 +1089,9 @@ export const makeSocket = (config: SocketConfig) => {
 		clearInterval(keepAliveReq)
 		clearTimeout(qrTimer)
 
+		// Stop session cleanup scheduler
+		sessionCleanup.stop()
+
 		// Clean up unified session manager
 		unifiedSessionManager?.destroy()
 
@@ -1448,6 +1461,9 @@ export const makeSocket = (config: SocketConfig) => {
 		recordConnectionAttempt('success')
 		incrementActiveConnections()
 
+		// Start session cleanup scheduler
+		sessionCleanup.start()
+
 		// Update server time offset from success node
 		const serverTime = extractServerTime(node)
 		if (serverTime) {
@@ -1572,6 +1588,7 @@ export const makeSocket = (config: SocketConfig) => {
 		ev,
 		authState: { creds, keys },
 		signalRepository,
+		sessionCleanup,
 		get user() {
 			return authState.creds.me
 		},