feat(video): redact transcript fields in the in-memory pending-request snapshot (#12430 item 6)

trackPendingRequest (open-sse/handlers/chatCore.ts) stored the raw client
body (with video transcript/audioTranscript cues) under `clientRequest`,
live-exposed via /api/usage/call-logs (pendingDetails), /api/logs/[id] and
/api/conversations while a request is in-flight. P2a redacted the persisted
detailed-log snapshot but not this in-memory copy.

Add redactPendingBody() to videoBridgeSnapshotRedaction.ts (sibling to
logClientRawRequestRedacted from P2a): when videoBridgeObserved, returns the
redacted clone from redactVideoTranscriptFieldsForLog; otherwise returns the
exact same reference. Wire it into the trackPendingRequest call site
(chatCore.ts:934), keeping the file within its frozen 5976-line budget
(5971 -> 5974).

open-sse/handlers/chatCore.ts

@@ -360,7 +360,10 @@ import { deleteSessionAccountAffinity } from "@/lib/db/sessionAccountAffinity";
 import { getCacheControlSettings } from "@/lib/cacheControlSettings";
 import { guardrailRegistry } from "@/lib/guardrails";
 import type { VideoBridgeLogRedactionEntry } from "@/lib/guardrails/videoBridge";
-import { logClientRawRequestRedacted } from "@/lib/guardrails/videoBridgeSnapshotRedaction";
+import {
+  logClientRawRequestRedacted,
+  redactPendingBody,
+} from "@/lib/guardrails/videoBridgeSnapshotRedaction";
 import {
   shouldPreserveCacheControl,
   resolveConnectionCacheOverride,
@@ -928,7 +931,7 @@ export async function handleChatCore({
   const pendingRequestId =
     trackPendingRequest(model, provider, pendingConnId, true, {
       clientEndpoint: clientRawRequest?.endpoint || "/v1/chat/completions",
-      clientRequest: clientRawRequest?.body ?? body,
+      clientRequest: redactPendingBody(clientRawRequest?.body ?? body, videoBridgeObserved),
       providerRequest: initialProviderRequest,
       stage: "registered",
       correlationId,

src/lib/guardrails/videoBridgeSnapshotRedaction.ts

@@ -133,3 +133,17 @@ export function logClientRawRequestRedacted(
     clientRawRequest.headers
   );
 }
+
+/**
+ * Call-site wrapper for the `clientRequest` field stored by `trackPendingRequest`
+ * (open-sse/handlers/chatCore.ts): the sibling in-memory leak to
+ * `logClientRawRequestRedacted` above — same raw body, but live-exposed via
+ * /api/usage/call-logs (pendingDetails), /api/logs/[id] and /api/conversations
+ * while the request is in-flight, not just in the persisted detailed-log
+ * snapshot. Identical observed/non-observed branching: a non-observed request
+ * keeps the exact same reference (no clone); an observed one gets the redacted
+ * clone.
+ */
+export function redactPendingBody(clientRequest: unknown, videoBridgeObserved: boolean): unknown {
+  return videoBridgeObserved ? redactVideoTranscriptFieldsForLog(clientRequest) : clientRequest;
+}

tests/unit/guardrails/videoBridgeSnapshotRedaction.test.ts

@@ -7,7 +7,10 @@
 import assert from "node:assert/strict";
 import test from "node:test";
 
-import { redactVideoTranscriptFieldsForLog } from "../../../src/lib/guardrails/videoBridgeSnapshotRedaction.ts";
+import {
+  redactVideoTranscriptFieldsForLog,
+  redactPendingBody,
+} from "../../../src/lib/guardrails/videoBridgeSnapshotRedaction.ts";
 // Heavy import is fine here (test only, never in the production module under test) — used
 // solely to prove the local placeholder literal never drifts from the canonical P1 constant.
 import { VIDEO_TRANSCRIPT_REDACTION_PLACEHOLDER } from "../../../src/lib/guardrails/videoBridgeHelpers.ts";
@@ -205,3 +208,57 @@ test("the redaction placeholder matches the canonical P1 constant (no drift)", (
   const part = contentAt(result, "messages", 0)[0];
   assert.equal(part.transcript, VIDEO_TRANSCRIPT_REDACTION_PLACEHOLDER);
 });
+
+// #12430 item 6 (P2c): the sibling in-memory leak. `trackPendingRequest`
+// (open-sse/handlers/chatCore.ts) stores the same raw client body under
+// `clientRequest`, live-exposed via /api/usage/call-logs (pendingDetails),
+// /api/logs/[id] and /api/conversations while the request is in-flight. This
+// helper is the guarded call-site wrapper chatCore.ts uses, mirroring
+// logClientRawRequestRedacted's observed/non-observed branching.
+test("redactPendingBody: observed=true delegates to redactVideoTranscriptFieldsForLog", () => {
+  const body = {
+    messages: [
+      {
+        role: "user",
+        content: [
+          {
+            type: "input_video",
+            video_url: "https://example.com/clip.mp4",
+            transcript: { cues: [{ text: "pending secret" }] },
+          },
+        ],
+      },
+    ],
+  };
+
+  const result = redactPendingBody(body, true);
+  assert.notEqual(
+    result,
+    body,
+    "observed path must return a new structure, not the same reference"
+  );
+  const part = contentAt(result, "messages", 0)[0];
+  assert.equal(part.transcript, VIDEO_TRANSCRIPT_REDACTION_PLACEHOLDER);
+  assert.ok(!JSON.stringify(result).includes("pending secret"));
+  assert.deepEqual(result, redactVideoTranscriptFieldsForLog(body));
+});
+
+test("redactPendingBody: observed=false returns the SAME reference unchanged", () => {
+  const body = {
+    messages: [
+      {
+        role: "user",
+        content: [
+          {
+            type: "input_video",
+            video_url: "https://example.com/clip.mp4",
+            transcript: { cues: [{ text: "not observed" }] },
+          },
+        ],
+      },
+    ],
+  };
+
+  const result = redactPendingBody(body, false);
+  assert.equal(result, body, "non-observed path must return the exact same reference");
+});