fix(signal): critical fixes for identity key detection - batch 1

High Priority Fixes based on Copilot/Codex code review:

1. Propagate errorCode to shouldRecreateSession (CRITICAL)
   - Extract error attribute from retry node
   - Pass errorCode to shouldRecreateSession in both sendRetryRequest and sendMessagesAgain
   - Without this fix, MAC error detection was NOT working
   - Now immediate session recreation works for MAC errors

2. Use .unref() on metrics interval
   - Prevents blocking process exit in short-lived scripts/tests
   - Interval no longer keeps event loop alive unnecessarily

3. Reset circuit breaker regardless of state
   - Previously only reset when isOpen()
   - Now resets in any state (open, half-open, or closed with accumulated failures)
   - Ensures clean slate after identity change detection

https://claude.ai/code/session_01SWAcNuGZQmEKyBPYkBhVHg

src/Signal/libsignal.ts

@@ -255,9 +255,9 @@ export function makeLibSignalRepository(
 		metrics.signalIdentityKeyCacheSize?.set(identityKeyCache.size)
 	}, 60000) // Every minute
 
-	// Cleanup interval on process exit
-	if (typeof process !== 'undefined') {
-		process.on('beforeExit', () => clearInterval(cacheMetricsInterval))
+	// Allow process to exit even with interval active (prevents blocking in short-lived scripts/tests)
+	if (typeof cacheMetricsInterval.unref === 'function') {
+		cacheMetricsInterval.unref()
 	}
 
 	const storage = signalStorage(auth, lidMapping, identityKeyCache, ev, preKeyCircuitBreaker, logger)
@@ -334,7 +334,8 @@ export function makeLibSignalRepository(
 								)
 
 								// Reset prekey circuit breaker since we identified the cause
-								if (preKeyCircuitBreaker?.isOpen()) {
+								// Reset regardless of state (could be open, half-open, or closed with accumulated failures)
+								if (preKeyCircuitBreaker) {
 									preKeyCircuitBreaker.reset()
 									logger.debug({ jid }, 'Reset prekey circuit breaker after identity key change detection')
 								}