[FEATURE] Images shown in chat need click-to-zoom / open-at-full-resolution - tiny previews make visual work impossible

Problem

When Claude sends image files into the conversation (SendUserFile / inline image results), the client renders them very small, and clicking an image does not open it at full resolution. There is no zoom, no 1:1 pixel view, and no 'open in system viewer' affordance.

This breaks a whole class of real workflows. Concrete example from today: Claude generated side-by-side art comparisons (2448x656 px) so I could judge line sharpness between an original sprite and an AI-upscaled variant of it. The decision literally depends on seeing pixels at 1:1. In the app the image renders at a fraction of its size and clicking it shows it only slightly larger, so I had to ask Claude for the file path and open every image manually in an external viewer to make the call.

Expected

• Click an image to open it at full resolution (lightbox with zoom/pan, or hand off to the system image viewer)
• Ideally a 1:1 / 'actual pixels' toggle for judging sharpness

Environment

• Claude Code via WSL2 (Ubuntu) on Windows 11, images delivered with SendUserFile
• Related but not identical: #70619 (images not clickable/openable, macOS), #78709 (broken SendUserFile thumbnails, Windows desktop)