fix(gateway): reconcile attachment offload rebase

src/gateway/chat-attachments.test.ts

@@ -8,7 +8,9 @@ const saveMediaBufferMock = vi.hoisted(() =>
     contentType: mime,
   })),
 );
-const deleteMediaBufferMock = vi.hoisted(() => vi.fn(async () => undefined));
+const deleteMediaBufferMock = vi.hoisted(() =>
+  vi.fn(async (_id: string, _subdir?: string) => undefined),
+);
 
 vi.mock("../media/store.js", async (importOriginal) => {
   const actual = (await importOriginal()) as Record<string, unknown>;

src/gateway/chat-attachments.ts

@@ -271,7 +271,12 @@ export async function parseMessageWithAttachments(
         labelMime ||
         "application/octet-stream";
 
-      if (sniffedMime && providedMime && sniffedMime !== providedMime) {
+      if (
+        sniffedMime &&
+        providedMime &&
+        !isGenericContainerMime(providedMime) &&
+        sniffedMime !== providedMime
+      ) {
         const usedSource =
           finalMime === sniffedMime
             ? "sniffed"
@@ -309,7 +314,11 @@ export async function parseMessageWithAttachments(
         );
       }
 
-      if (shouldForceImageOffload && isImage && textOnlyImageOffloadCount >= TEXT_ONLY_OFFLOAD_LIMIT) {
+      if (
+        shouldForceImageOffload &&
+        isImage &&
+        textOnlyImageOffloadCount >= TEXT_ONLY_OFFLOAD_LIMIT
+      ) {
         log?.warn(
           `attachment ${label}: dropping image because text-only offload limit ` +
             `${TEXT_ONLY_OFFLOAD_LIMIT} was reached`,
@@ -318,7 +327,8 @@ export async function parseMessageWithAttachments(
         continue;
       }
 
-      const shouldOffload = shouldForceImageOffload || !isImage || sizeBytes > OFFLOAD_THRESHOLD_BYTES;
+      const shouldOffload =
+        shouldForceImageOffload || !isImage || sizeBytes > OFFLOAD_THRESHOLD_BYTES;
 
       if (!shouldOffload) {
         images.push({ type: "image", data: b64, mimeType: finalMime });

src/gateway/server-methods/chat.directive-tags.test.ts

@@ -2022,10 +2022,8 @@ describe("chat directive tag stripping for non-streaming final payloads", () =>
           }
         | undefined;
       expect(mockState.lastDispatchImages).toBeUndefined();
-      expect(mockState.lastDispatchImageOrder).toEqual(["offloaded"]);
-      expect(mockState.lastDispatchCtx?.Body).toMatch(
-        /^summarize this\n\[media attached: media:\/\/inbound\//,
-      );
+      expect(mockState.lastDispatchImageOrder).toBeUndefined();
+      expect(mockState.lastDispatchCtx?.Body).toBe("summarize this");
       expect(mockState.savedMediaCalls).toEqual([
         expect.objectContaining({
           contentType: "application/pdf",
@@ -2033,7 +2031,7 @@ describe("chat directive tag stripping for non-streaming final payloads", () =>
           size: expect.any(Number),
         }),
       ]);
-      expect(message?.content).toMatch(/^summarize this\n\[media attached: media:\/\/inbound\//);
+      expect(message?.content).toBe("summarize this");
       expect(message?.MediaPath).toBe("/tmp/chat-send-brief.pdf");
       expect(message?.MediaPaths).toEqual(["/tmp/chat-send-brief.pdf"]);
       expect(message?.MediaType).toBe("application/pdf");

src/gateway/server-methods/chat.ts

@@ -69,7 +69,7 @@ import {
   projectRecentChatDisplayMessages,
   resolveEffectiveChatHistoryMaxChars,
 } from "../chat-display-projection.js";
-import { stripEnvelopeFromMessage, stripEnvelopeFromMessages } from "../chat-sanitize.js";
+import { stripEnvelopeFromMessage } from "../chat-sanitize.js";
 import { augmentChatHistoryWithCliSessionImports } from "../cli-session-history.js";
 import { isSuppressedControlReplyText } from "../control-reply-text.js";
 import {