[BUG] VSCode extension reverses multi-image upload order and normalizes filenames to image.png

Summary

When attaching multiple images in a single message via the Claude Code VSCode extension, two things break:

1. Images are delivered to the model in reverse order vs. the order they were attached.
2. All filenames are normalized to image.png, losing any original naming that could disambiguate them.

Together these remove every way to refer to a specific image in a multi-image upload by position or filename. The user is forced to rely entirely on in-image content (text labels, distinctive pixels) to tell the model "this is image 1, this is image 2, ...", which fails for near-identical screenshots.

Steps to reproduce

1. Open Claude Code in VSCode.
2. In the input area, attach 3 distinct images in a specific order, e.g. by dragging files named left.png, middle.png, right.png left-to-right.
3. Write a prompt that refers to them by position: "I uploaded them left to right: left = A, middle = B, right = C."
4. Send the message.
5. Ask the model what filenames it received and what order it sees them in.

Expected

• Images delivered in attach order.
• Original filenames preserved (or at least unique, distinguishable identifiers per image).

Actual

• Images arrive at the model in reverse order (last attached → first).
• Filenames are all image.png, identical across attachments — no way to disambiguate.
• Any prompt that says "the first image shows X, the second shows Y" is silently mis-aligned.

Impact

High when uploading screenshot sequences (game runtime logs, stepwise UI states, debugging captures). Forces workarounds:

• Collaging multiple frames into a single image, or
• Overlaying a #1, #2, #3 label inside each screenshot.

Both are extra manual work per session.

Environment

• OS: Windows 11 Enterprise 10.0.26100
• Claude Code: VSCode extension
• Model: claude-opus-4-7[1m]

Suggested fix

• Preserve attach order in the multipart message sent to the model.
• Preserve (or auto-number) original filenames: image_1.png, image_2.png, … if the source name is unavailable.