feat: add remanso CLI package and update GitHub Action
- Fix ../ relative path normalization in resolveInternalLinks and
findPostsWithStaleLinks (packages/cli/src/extensions/remanso.ts)
- Add packages/remanso: new CLI binary (remanso-cli npm package, remanso
command) with auth, init, publish, sync, and github commands
- publish: two-pass flow (site.standard.document + space.remanso.note),
.pub.md filter, siteUrl derived from agent DID, app-password only
- sync: matches .pub.md files to PDS documents, preserves note field comparison
- init: interactive wizard with GitHub remote detection, credential setup,
publication create/select, .gitignore, workflow generation, gh secret setup
- github: generates remanso-space/sequoia@main workflow YAML, sets secrets via gh CLI
- Update action.yml to build and link remanso CLI instead of sequoia CLI
- Add build:remanso and dev:remanso scripts to root package.json