feat: Image/screenshot support in mobile app

[michelhelsdingen]

Feature Request

Support sending images/screenshots from the Happy mobile app to Claude Code sessions.

Use Case

When working with Claude Code via the Happy mobile app, I often want to share a screenshot (e.g., an error on screen, a UI element, App Store Connect pages) to give Claude visual context. Currently, only text messages are supported.

Current Workaround

None — I have to describe what I'm seeing in text, or switch to desktop.

Suggested Approach

1. Mobile app: Add image picker / camera / paste support, upload as base64 or multipart to the server
2. Happy server: Receive image, save to a temp path on the machine running Claude Code
3. Claude Code: Pass the file path so Claude can read it via its native image support (Read tool handles PNG/JPG)

Context

Claude Code already supports reading images natively — the gap is getting the image from the mobile app to the local filesystem where Claude can access it.

Environment

• Happy CLI: v0.14.1-0
• Claude Code: 2.1.39
• Platform: iOS (Happy mobile app)