fix(signal): replace  with @uuid/@phone from mentions

Related #1926

Signal mentions were appearing as  (object replacement character)
instead of readable identifiers. This caused Clawdbot to misinterpret
messages and respond inappropriately.

Now parses dataMessage.mentions array and replaces the placeholder
character with @{uuid} or @{phone} from the mention metadata.

src/signal/monitor/event-handler.ts

@@ -352,7 +352,23 @@ export function createSignalEventHandler(deps: SignalEventHandlerDeps) {
       : deps.isSignalReactionMessage(dataMessage?.reaction)
         ? dataMessage?.reaction
         : null;
-    const messageText = (dataMessage?.message ?? "").trim();
+
+    // Replace  (object replacement character) with @uuid or @phone from mentions
+    let messageText = (dataMessage?.message ?? "").trim();
+    if (messageText && dataMessage?.mentions?.length) {
+      const mentions = dataMessage.mentions
+        .filter((m) => (m.uuid || m.number) && m.start != null && m.length != null)
+        .sort((a, b) => (b.start ?? 0) - (a.start ?? 0)); // Reverse order to avoid index shifting
+
+      for (const mention of mentions) {
+        const start = mention.start!;
+        const length = mention.length!;
+        const identifier = mention.uuid || mention.number || "";
+        const replacement = `@${identifier}`;
+        messageText = messageText.slice(0, start) + replacement + messageText.slice(start + length);
+      }
+    }
+
     const quoteText = dataMessage?.quote?.text?.trim() ?? "";
     const hasBodyContent =
       Boolean(messageText || quoteText) || Boolean(!reaction && dataMessage?.attachments?.length);

src/signal/monitor/event-handler.types.ts

@@ -16,10 +16,19 @@ export type SignalEnvelope = {
   reactionMessage?: SignalReactionMessage | null;
 };
 
+export type SignalMention = {
+  name?: string | null;
+  number?: string | null;
+  uuid?: string | null;
+  start?: number | null;
+  length?: number | null;
+};
+
 export type SignalDataMessage = {
   timestamp?: number;
   message?: string | null;
   attachments?: Array<SignalAttachment>;
+  mentions?: Array<SignalMention> | null;
   groupInfo?: {
     groupId?: string | null;
     groupName?: string | null;