fix: keep sandbox reply fallback narrow

src/auto-reply/reply/reply-media-paths.test.ts

@@ -94,6 +94,34 @@ describe("createReplyMediaPathNormalizer", () => {
     );
   });
 
+  it("drops sandbox-mapped media when staging fails instead of retrying the workspace fallback", async () => {
+    ensureSandboxWorkspaceForSession.mockResolvedValue({
+      workspaceDir: "/tmp/sandboxes/session-1",
+      containerWorkdir: "/workspace",
+    });
+    resolveOutboundAttachmentFromUrl.mockRejectedValueOnce(new Error("media too large"));
+    const normalize = createReplyMediaPathNormalizer({
+      cfg: {},
+      sessionKey: "session-key",
+      workspaceDir: "/tmp/agent-workspace",
+    });
+
+    const result = await normalize({
+      mediaUrls: ["./out/photo.png"],
+    });
+
+    expect(result).toMatchObject({
+      mediaUrl: undefined,
+      mediaUrls: undefined,
+    });
+    expect(resolveOutboundAttachmentFromUrl).toHaveBeenCalledTimes(1);
+    expect(resolveOutboundAttachmentFromUrl).toHaveBeenCalledWith(
+      path.join("/tmp/sandboxes/session-1", "out", "photo.png"),
+      5 * 1024 * 1024,
+      expect.any(Object),
+    );
+  });
+
   it("drops host file URLs when no sandbox mapping applies", async () => {
     const normalize = createReplyMediaPathNormalizer({
       cfg: {},

src/auto-reply/reply/reply-media-paths.ts

@@ -180,13 +180,12 @@ export function createReplyMediaPathNormalizer(params: {
       !WINDOWS_DRIVE_RE.test(media);
     const sandboxRoot = await resolveSandboxRoot();
     if (sandboxRoot) {
+      let sandboxResolvedMedia: string;
       try {
-        return await persistLocalReplyMedia(
-          await resolveSandboxedMediaSource({
-            media,
-            sandboxRoot,
-          }),
-        );
+        sandboxResolvedMedia = await resolveSandboxedMediaSource({
+          media,
+          sandboxRoot,
+        });
       } catch (err) {
         if (!isLikelyLocalMediaSource(media)) {
           throw err;
@@ -202,6 +201,7 @@ export function createReplyMediaPathNormalizer(params: {
         }
         return await persistLocalReplyMedia(media);
       }
+      return await persistLocalReplyMedia(sandboxResolvedMedia);
     }
     if (isRelativeLocalMedia) {
       return await persistLocalReplyMedia(resolveWorkspaceRelativeMedia(media));