Image dimension limit (2000px) hard-fails multi-image sessions

Description

When a Claude Code session contains multiple images and at least one exceeds 2000px on any side, the turn hard-fails with:

An image in the conversation exceeds the dimension limit for many-image requests (2000px). Start a new session with fewer images.

The only workaround is starting a new session, which loses all context. This is very disruptive for mobile/UI work where screenshots routinely exceed 2000px on the long side (modern phones: 2412×1080, 2556×1179, 2796×1290, plus 2x/3x Figma exports and adb exec-out screencap / xcrun simctl io screenshot output).

Requested behavior

Any of these would fix it:

• Auto-downscale images client-side to fit the limit before sending, instead of hard-failing the whole turn.
• Drop/skip only the oversized image with a warning and keep the session alive.
• Raise the limit — modern device screenshots already sit near or above it by default.

Repro

1. Run Claude Code on a Flutter/iOS/Android project.
2. Take several screenshots from a modern device via adb exec-out screencap -p or xcrun simctl io <udid> screenshot.
3. Read them into the session one after another with the Read tool.
4. After a few images, the next turn hard-fails with the error above.

Environment

• Claude Code CLI on macOS (Darwin 25.4.0)
• Model: claude-opus-4-7 (1M context)
• Frequent on mobile UI workflows that rely on repeated runtime screenshots.

Impact

High for mobile / UI developers. Runtime-verification workflows (screenshot → tap → screenshot → iterate) are impossible to complete in one session because the 2000px cap is reached almost immediately.