fix(signal): sanitize internal tool-trace lines from outbound text (#97360)

Wrap the signal outbound sanitizeText hook with sanitizeAssistantVisibleText so assistant internal tool-trace scaffolding is stripped before delivery, matching the sibling channel fixes under #90684 (Telegram #95774, Google Chat #95084, IRC #97214).

extensions/signal/src/channel.ts

@@ -22,6 +22,7 @@ import {
   createDefaultChannelRuntimeState,
 } from "openclaw/plugin-sdk/status-helpers";
 import { normalizeLowercaseStringOrEmpty } from "openclaw/plugin-sdk/string-coerce-runtime";
+import { sanitizeAssistantVisibleText } from "openclaw/plugin-sdk/text-chunking";
 import { resolveSignalAccount, type ResolvedSignalAccount } from "./accounts.js";
 import {
   shouldSuppressLocalSignalExecApprovalPrompt,
@@ -461,6 +462,7 @@ export const signalPlugin: ChannelPlugin<ResolvedSignalAccount, SignalProbe> =
         chunker: chunkText,
         chunkerMode: "text",
         textChunkLimit: 4000,
+        sanitizeText: ({ text }) => sanitizeAssistantVisibleText(text),
         shouldSuppressLocalPayloadPrompt: ({ cfg, accountId, payload, hint }) =>
           shouldSuppressLocalSignalExecApprovalPrompt({
             cfg,

extensions/signal/src/outbound-tool-trace-sanitize.test.ts

@@ -0,0 +1,19 @@
+// Signal outbound must strip assistant internal tool-trace scaffolding, matching
+// the sibling channel fixes tracked under #90684 (Telegram #95774 / Google Chat
+// #95084 / IRC #97214). Signal is plaintext-only, so leaked traces are verbatim.
+import { describe, expect, it } from "vitest";
+import { signalPlugin } from "./channel.js";
+
+describe("signal outbound sanitizeText", () => {
+  it("strips internal tool-trace banners before outbound delivery", () => {
+    const text = "Done.\n⚠️ 🛠️ `search repos (agent)` failed";
+
+    expect(signalPlugin.outbound?.sanitizeText?.({ text, payload: { text } })).toBe("Done.");
+  });
+
+  it("preserves ordinary assistant prose while sanitizing", () => {
+    const text = "The pipeline has 3 open deals.";
+
+    expect(signalPlugin.outbound?.sanitizeText?.({ text, payload: { text } })).toBe(text);
+  });
+});