Refine roadmap issue presentation

[jmchilton]

Summary

• prefix every main and substep link with its GitHub issue number
• omit the Substeps section entirely when a roadmap main has no native substeps
• update the validator and focused tests to enforce both presentation rules
• refresh roadmap and validation-document revisions

Issue metadata updated first

• Document Galaxy list-of-record collections for reference data #225: Document Galaxy list-of-record collections for reference data
• Design a Claude dynamic-workflow projection for Foundry Pipelines #308: Design a Claude dynamic-workflow projection for Foundry Pipelines

The live title changes were applied before updating the Markdown, and the live validator now agrees with all 20 mains and 13 substeps.

Verification

• npm run validate:roadmap
• pnpm exec vitest run tests/roadmap.test.ts — 12 passed
• npm run test — 386 passed
• npm run validate — 0 errors
• npm run typecheck
• npm run format
• npm run lint
• npm run site:build