feat(whatsapp): add sendReadReceipts config option

Add option to disable automatic read receipts for WhatsApp messages.
When set to false, Clawdbot will not mark messages as read (blue ticks).

Closes #344

Changes:
- Add sendReadReceipts to WhatsAppConfig and WhatsAppAccountConfig types
- Add sendReadReceipts to zod schemas for validation
- Add sendReadReceipts to ResolvedWhatsAppAccount with fallback chain
- Pass sendReadReceipts through to monitorWebInbox
- Gate sock.readMessages() call based on config option

Default behavior (true) is preserved - only explicitly setting false
will disable read receipts.

src/web/inbound/monitor.ts

@@ -26,6 +26,8 @@ export async function monitorWebInbox(options: {
   authDir: string;
   onMessage: (msg: WebInboundMessage) => Promise<void>;
   mediaMaxMb?: number;
+  /** Send read receipts for incoming messages (default true). */
+  sendReadReceipts?: boolean;
 }) {
   const inboundLogger = getChildLogger({ module: "web-inbound" });
   const inboundConsoleLog = createSubsystemLogger("gateway/channels/whatsapp").child("inbound");
@@ -139,7 +141,11 @@ export async function monitorWebInbox(options: {
       });
       if (!access.allowed) continue;
 
-      if (id && !access.isSelfChat) {
+      if (
+        id &&
+        !access.isSelfChat &&
+        options.sendReadReceipts !== false
+      ) {
         const participant = msg.key?.participant;
         try {
           await sock.readMessages([{ remoteJid, id, participant, fromMe: false }]);