#4725 swamp skill references still point to separate skills that were merged into the swamp skill

Most reference guides in the bundled swamp skill end with a When to Use Other Skills table, or prose such as see the swamp-workflow skill, naming separate skills (swamp-workflow, swamp-model, swamp-extension, swamp-repo, swamp-data, swamp-troubleshooting). Those skills no longer exist: they are now reference folders inside the single swamp skill (references//guide.md). An agent following one of these pointers looks for a skill that is not installed.

Affected files (grep for Use Skill or for the old skill names): references/behavior/reference.md, data/reference.md, extension/reference.md, issue/reference.md, repo/reference.md, report/reference.md, troubleshooting/reference.md, workflow/reference.md, vault/reference.md and extension-publish/references/publishing.md.

Fix: replace each table and mention with a relative link to the matching references//guide.md, consistently across all files. Found while triaging swamp-club#4721, which fixes only the vault workflow pointer.