Bug: `SendUserFile` reports success but delivers nothing (VS Code extension)

Environment

• Claude Code CLI: 2.1.207 (upgraded from 2.1.205 during this investigation; issue reproduced on both versions)
• Client: Claude Code VS Code native extension
• OS: macOS (Darwin 25.5.0)

Description
Calling the SendUserFile tool always returns a success message (e.g. "1 file delivered to user." / "2 files delivered to user."), but the file/image never actually appears in the VS Code side panel or anywhere else visible to the user. The tool's response gives no indication that delivery failed, so there's no error signal to act on.

Steps to reproduce

1. In a Claude Code session running inside the VS Code extension, call SendUserFile with a small local PNG, display: "render", status: "normal".
2. Observe the tool result: success message returned.
3. Ask the user to confirm whether the image appeared. It does not.
4. Repeat with a second call (image + a plain text file, display: "render"). Same result: success message, nothing appears for either file.

Expected behavior
The image should render inline in the side panel (per the tool's own documented display: "render" behavior), or the text file should appear as an attachment.

Actual behavior
Nothing appears client-side despite a "delivered" success response, across repeated attempts and file types.

Additional notes

• This was independently reproduced in more than one project/session over time, always with the same "delivered" response and no visible file on the user's end. That suggests it isn't a one-off timing issue but a consistent break between the tool's success acknowledgment and the actual rendering/delivery step in the VS Code extension client.
• Workaround currently in use: shelling out to open <path> (macOS) to display images via the default system viewer instead of relying on SendUserFile.
• Happy to provide additional session transcript detail if useful for debugging (redacted of any project-specific content).