personal memory agent

docs: rename repo solstone → solstone-journal (PyPI unchanged) master

- README heading: `# solstone` → `# solstone journal` + 1-line journal-layer framing clause; tagline preserved. - Update github.com/solpbc/solstone → solstone-journal in README, INSTALL, CONTRIBUTING, DATA-FLOW, pyproject.toml (project.urls), parakeet hints. - Migrate vit beacon `vit:github.com/solpbc/solstone` → solstone-journal in .vit/config.json + solstone/talent/vit/SKILL.md. PyPI package name unchanged; CHANGELOG historical refs preserved; tests referencing other solstone-* repos untouched. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>