feat: add automatic CTWA (Click-to-WhatsApp) ads message recovery

Messages from Facebook/Instagram ads (Click-to-WhatsApp) don't arrive on
linked devices because Meta's ads endpoint doesn't encrypt for multi-device.
They arrive as "Message absent from node" placeholders.

This change automatically requests the message from the primary phone via
PDO (Peer Data Operation) when a CTWA placeholder is detected.

Changes:
- Add enableCTWARecovery config option (default: true)
- Trigger requestPlaceholderResend() for "Message absent from node" errors
- Add Prometheus metrics for CTWA recovery tracking
- Add comprehensive unit tests for CTWA recovery functionality

Resolves: https://github.com/WhiskeySockets/Baileys/issues/1723
Resolves: https://github.com/WhiskeySockets/Baileys/issues/1034

src/Utils/prometheus-metrics.ts

@@ -1385,6 +1385,24 @@ export const metrics = {
 		new Gauge('messages_queued', 'Current number of messages in queue', ['priority'])
 	),
 
+	// ========== CTWA (Click-to-WhatsApp Ads) Metrics ==========
+	/**
+	 * Messages from Facebook/Instagram ads that arrive as placeholder messages
+	 * and are recovered via PDO (Peer Data Operation) request
+	 */
+	ctwaRecoveryRequests: baileysMetrics.register(
+		new Counter('ctwa_recovery_requests_total', 'Total CTWA placeholder resend requests', ['status'])
+	),
+	ctwaMessagesRecovered: baileysMetrics.register(
+		new Counter('ctwa_messages_recovered_total', 'Total CTWA messages successfully recovered')
+	),
+	ctwaRecoveryLatency: baileysMetrics.register(
+		new Histogram('ctwa_recovery_latency_ms', 'CTWA message recovery latency in ms', [], [500, 1000, 2000, 3000, 5000, 8000, 10000])
+	),
+	ctwaRecoveryFailures: baileysMetrics.register(
+		new Counter('ctwa_recovery_failures_total', 'Total CTWA recovery failures', ['reason'])
+	),
+
 	// ========== Media Metrics ==========
 	mediaUploads: baileysMetrics.register(
 		new Counter('media_uploads_total', 'Total media uploads', ['type', 'status'])