fix(whatsapp): propagate fromMe through inbound message pipeline

The `fromMe` flag from Baileys' WAMessage.key was only used for
access-control filtering and then discarded.  This meant agents
could not distinguish owner-sent messages from contact messages
in DM conversations (everything appeared as from the contact).

Add `fromMe` to `WebInboundMessage`, store it during message
construction, and thread it through `buildInboundLine` →
`formatInboundEnvelope` so DM transcripts prefix owner messages
with `(self):`.

Closes #32061

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/auto-reply/envelope.ts

@@ -197,12 +197,18 @@ export function formatInboundEnvelope(params: {
   sender?: SenderLabelParams;
   previousTimestamp?: number | Date;
   envelope?: EnvelopeFormatOptions;
+  fromMe?: boolean;
 }): string {
   const chatType = normalizeChatType(params.chatType);
   const isDirect = !chatType || chatType === "direct";
   const resolvedSenderRaw = params.senderLabel?.trim() || resolveSenderLabel(params.sender ?? {});
   const resolvedSender = resolvedSenderRaw ? sanitizeEnvelopeHeaderPart(resolvedSenderRaw) : "";
-  const body = !isDirect && resolvedSender ? `${resolvedSender}: ${params.body}` : params.body;
+  const body =
+    isDirect && params.fromMe
+      ? `(self): ${params.body}`
+      : !isDirect && resolvedSender
+        ? `${resolvedSender}: ${params.body}`
+        : params.body;
   return formatAgentEnvelope({
     channel: params.channel,
     from: params.from,