Upload images to img402.dev for embedding in GitHub PRs, issues, and comments. Images under 1MB are uploaded free (no payment, no auth) and persist for 7 days. Use when the agent needs to share an image in a GitHub context — screenshots, mockups, diagrams, or any visual. Triggers: "screenshot this", "attach an image", "add a screenshot to the PR", "upload this mockup", or any task producing an image for GitHub.