fix(socket): move PreKey sync reschedule check inside finally block

Minimizes race window between isRunning=false and reschedule check by
moving the setTimeout reschedule logic inside the finally block.

Changes:
- Move reschedule check (if !closed && !cleanedUp && ws.isOpen) from
  after finally block to inside finally block
- Reduces race window where end() could be called between finally and check

Timeline before fix:
T0: syncLoop finally executes → isRunning = false
T1: end() called → closed = true
T2: syncLoop checks if (!closed) ← sees false
T3: setTimeout scheduled ← orphaned timer
T4: cleanupPreKeyAutoSync() clears it

Timeline after fix:
T0: syncLoop finally executes → isRunning = false
T1: Immediately checks flags INSIDE finally (atomic)
T2: Window too small for race condition

Risk: LOW (cleanup function already handles orphaned timers)
Impact: Cleaner code, minimizes theoretical race window

https://claude.ai/code/session_VMxqX

src/Socket/socket.ts

@@ -766,12 +766,12 @@ export const makeSocket = (config: SocketConfig) => {
 				logger.error({ error }, '🔑 PreKey auto-sync failed')
 			} finally {
 				isRunning = false
-			}
 
-			// PROTECTION 3: Prevent timer accumulation and post-cleanup rescheduling
-			// Check cleanedUp flag atomically to prevent race condition
-			if (!closed && !cleanedUp && ws.isOpen) {
-				syncTimer = setTimeout(syncLoop, SYNC_INTERVAL)
+				// PROTECTION 3: Prevent timer accumulation and post-cleanup rescheduling
+				// Check cleanedUp flag atomically INSIDE finally to minimize race window
+				if (!closed && !cleanedUp && ws.isOpen) {
+					syncTimer = setTimeout(syncLoop, SYNC_INTERVAL)
+				}
 			}
 		}