- Project card: optional `repo` field renders a git icon corner link
(github.com / bitbucket.org / Gitea URLs supported).
- All cards: `.card__title` and `.card__desc` are now display:block, so
the description always starts on its own line.
- Added data/links.schema.json (JSON Schema 2020-12) describing the
full content model. Both data files reference it via `$schema` for
github.dev / VS Code autocomplete.
- New GitHub Action validates data/links.json on every push/PR:
jq syntax check + ajv-cli schema validation.
