fix(typescript): resolve compilation errors for production build

Fixes 4 TypeScript compilation errors preventing successful build:

## Errors Fixed

### 1. lid-mapping.ts:799 - Property 'metricsModule' does not exist
**Error**: `this.metricsModule = null` in destroy() but property never declared
**Fix**: Removed orphaned line from previous metrics cleanup
**Impact**: Allows successful compilation

### 2-3. socket.ts:795,817 - Connection handler type mismatch
**Error**: `{ connection: any }` not assignable to `Partial<ConnectionState>`
**Cause**: Destructuring makes 'connection' required but it's optional in Partial
**Fix**: Changed handlers to `(update: Partial<ConnectionState>)`
**Impact**: Proper type safety for connection.update events

### 4. event-buffer.ts:430 - Wrong argument order
**Error**: Object passed as second arg but logger expects (obj, msg) order
**Fix**: Swapped arguments to `logger.debug({ queuedCount }, 'message')`
**Impact**: Matches logger signature from structured-logger.ts

## Root Cause Analysis

All errors stem from incremental changes where:
- Removed metrics support but missed cleanup reference
- Added connection handlers without checking Partial<T> semantics
- Used logger without verifying parameter order

## Testing

Build verification:
```bash
npm run build  # Should now complete successfully
```

These are compilation errors only - no runtime behavior changes.

https://claude.ai/code/session_VMxqX

src/Signal/lid-mapping.ts

@@ -795,9 +795,6 @@ export class LIDMappingStore {
 		// Clear cache
 		this.mappingCache.clear()
 
-		// Clear metrics module reference
-		this.metricsModule = null
-
 		this.logger.debug('LIDMappingStore destroyed successfully')
 	}
 

src/Socket/socket.ts

@@ -12,7 +12,7 @@ import {
 	NOISE_WA_HEADER,
 	UPLOAD_TIMEOUT
 } from '../Defaults'
-import type { LIDMapping, SocketConfig } from '../Types'
+import type { ConnectionState, LIDMapping, SocketConfig } from '../Types'
 import { DisconnectReason } from '../Types'
 import {
 	addTransactionCapability,
@@ -777,11 +777,11 @@ export const makeSocket = (config: SocketConfig) => {
 
 		// PROTECTION 4: Initial delay (avoid duplicate at startup)
 		// CB:success already calls uploadPreKeysToServerIfRequired(), so wait 6h before first auto-sync
-		const connectionHandler = ({ connection }: { connection: any }) => {
-			if (connection === 'open') {
+		const connectionHandler = (update: Partial<ConnectionState>) => {
+			if (update.connection === 'open') {
 				logger.info('🔑 Starting PreKey auto-sync timer (first sync in 6h)')
 				syncTimer = setTimeout(syncLoop, SYNC_INTERVAL)
-			} else if (connection === 'close') {
+			} else if (update.connection === 'close') {
 				// PROTECTION 5: Cleanup on disconnect
 				if (syncTimer) {
 					clearTimeout(syncTimer)
@@ -814,8 +814,8 @@ export const makeSocket = (config: SocketConfig) => {
 	 * Returns cleanup function to remove event listener
 	 */
 	const startSessionTTL = () => {
-		const connectionHandler = ({ connection }: { connection: any }) => {
-			if (connection === 'open') {
+		const connectionHandler = (update: Partial<ConnectionState>) => {
+			if (update.connection === 'open') {
 				sessionStartTime = Date.now()
 
 				// PROTECTION 1: Long TTL (7 days)
@@ -840,7 +840,7 @@ export const makeSocket = (config: SocketConfig) => {
 
 				const ttlHours = SESSION_TTL / 1000 / 60 / 60
 				logger.info(`🕐 Session TTL started (${ttlHours}h = 7 days)`)
-			} else if (connection === 'close') {
+			} else if (update.connection === 'close') {
 				// PROTECTION 4: Cleanup ALL timers on disconnect
 				if (ttlTimer) {
 					clearTimeout(ttlTimer)

src/Utils/event-buffer.ts

@@ -427,7 +427,7 @@ export const makeEventBuffer = (
 	if (config.enableMetrics) {
 		import('./prometheus-metrics').then(m => {
 			metricsModule = m
-			logger.debug('📊 Prometheus metrics loaded, flushing buffered metrics', { queuedCount: metricsQueue.length })
+			logger.debug({ queuedCount: metricsQueue.length }, '📊 Prometheus metrics loaded, flushing buffered metrics')
 			// Flush buffered metrics
 			metricsQueue.forEach(fn => fn())
 			metricsQueue = []