feat: add Sonnet 5.5 Melon Jelly artifact and stop ignoring results/

[sv-tmueller]

Summary

• Adds the Claude Sonnet 5.5 result for game-melon-jelly (Add the Melon Jelly soft-body benchmark prompt #19): results/artifacts/melon-jelly_claude_sonnet_5_5.html, a single-file XPBD soft-body watermelon (about 950 particles, grab / pinch / knife / recolor).
• Removes results/ from .gitignore so benchmark output can be tracked without git add -f.

Notes

• The artifact was written directly by the model, not through run.py, so there are no latency, token or cost numbers.
• Checked in headless Chrome: drop, bounce and settle in about 2 s; cutting gives independent pieces; reset restores the scene; no NaNs under extreme parameters and wild dragging; no external dependencies.
• This branch is based on current main, which already contains the prompt from feat: add Melon Jelly soft-body benchmark prompt #20.

🤖 Generated with Claude Code