[CRITICAL] Potential deadlock: Context cancellation with mutex held.

Current:

walletsMtx.Lock()
defer walletsMtx.Unlock()
// ...
cancelMainCtx()
wg.Wait()

Issue: If any goroutine in wg tries to acquire walletsMtx (e.g., in wallet operations), it will deadlock because wg.Wait() is called while holding the mutex.

Suggested:

walletsMtx.Lock()
// ... close wallets ...
walletsMtx.Unlock()

// Cancel and wait AFTER releasing the mutex
cancelMainCtx()
wg.Wait()

logMtx.Lock()
// ... close logger ...

Why: Background goroutines must be able to acquire locks during shutdown. Holding locks during wg.Wait() is a common deadlock pattern.

[SUGGESTION] Initialization order could be improved.

Current: Context created after setting initialized = true flag (line 77).

Suggested: Move mainCtx, cancelMainCtx = context.WithCancel(context.Background()) to before setting initialized = true (around line 75).

Why: If initialization is checked between line 77 and 76, the context might not be ready. Minor race condition.

[WARNING] RLock held during potentially slow operation.

Current: logMtx.RLock() held during log.Debug() which may involve I/O.

Consider: If logging is fast and non-blocking in this implementation, this may be acceptable. However, best practice is to minimize lock duration.

Suggested pattern (if needed):

logMtx.RLock()
logger := log
logMtx.RUnlock()
logger.Debug("libwallet mobile shutting down")

Why: Avoid holding locks during I/O operations to prevent blocking other goroutines.