Image Vision Skill

Adds the ability for NanoClaw agents to see and understand images sent via WhatsApp. Images are downloaded, resized with sharp, saved to the group workspace, and passed to the agent as base64-encoded multimodal content blocks.

Phase 1: Pre-flight

1. Check if src/image.ts exists — skip to Phase 3 if already applied
2. Confirm sharp is installable (native bindings require build tools)

Prerequisite: WhatsApp must be installed first (skill/whatsapp merged). This skill modifies WhatsApp channel files.

Phase 2: Apply Code Changes

Ensure WhatsApp fork remote

git remote -v