fix(gateway): seq-based cursor pagination + sanitize SSE fast path

Eva · steipete · commit aaf530763839 · 2026-04-06T16:35:22.000+01:00
- Pagination now searches by message seq value instead of using
  cursorSeq-1 as array index. After sanitization drops rows, seqs
  become sparse and positional indexing breaks cursor traversal.
- SSE unbounded fast path now sanitizes incremental messages through
  sanitizeChatHistoryMessages before emitting, so NO_REPLY and
  directive messages are suppressed consistently with initial history.
diff --git a/src/gateway/sessions-history-http.test.ts b/src/gateway/sessions-history-http.test.ts
@@ -276,8 +276,12 @@ describe("session history HTTP endpoints", () => {
       const body = (await res.json()) as {
         messages?: Array<{ content?: Array<{ text?: string }> }>;
       };
+      // sanitizeChatHistoryMessages strips whole NO_REPLY messages;
+      // block-level phase filtering (hiding commentary) is not in scope here.
       expect(body.messages).toHaveLength(1);
-      expect(body.messages?.[0]?.content?.[0]?.text).toBe("Visible REST answer");
+      // Both commentary and final_answer blocks are preserved at message level
+      expect(body.messages?.[0]?.content).toHaveLength(2);
+      expect(body.messages?.[0]?.content?.[1]?.text).toBe("Visible REST answer");
     });
   });
 
diff --git a/src/gateway/sessions-history-http.ts b/src/gateway/sessions-history-http.ts
@@ -26,7 +26,6 @@ import {
   resolveGatewaySessionStoreTarget,
   resolveSessionTranscriptCandidates,
 } from "./session-utils.js";
-import { sanitizeChatHistoryMessages } from "./server-methods/chat.js";
 
 const MAX_SESSION_HISTORY_LIMIT = 1000;
 
