Add Grok, Kilo Code, and OpenHands session support

[xhluca]

Summary

• add discovery, parsing, normalized conversion, native writing, and resume support for Grok, Kilo Code, and OpenHands
• cover all 15 supported formats across 225 source/target routes
• validate imported sessions with pinned native binaries and real terminal UI trajectories
• document the three formats, caveats, and reproducible validation
• present all supported agents in a concise README logo table whose marks are hosted on the project website, not packaged in the MIT repository
• add pull-request CI for Python 3.11–3.13 and the website

Validation

• uv run pytest -q — 555 passed, 13 skipped
• exact pinned native replay/TUI suite — 3 passed
• uv run ruff check .
• uv run ruff format --check src tests scripts
• website build, lint, and rendered-page tests — 6 passed
• isolated wheel entry points and package-content audit
• desktop/mobile browser QA on the deployed GitHub Pages site