…igible

- Dashboard models: remove tier, currentTier, qualifiedUniqueReposCount,
  rawCredibility, credibilityScalar, repositoryUniquenessMultiplier,
  all bronze/silver/gold tier stats fields
- Add isEligible and credibility to MinerEvaluation
- Delete Predictions model and API
- Remove TierConfig from Configurations model and API
- Update leaderboard MinerStats type

Strip Bronze/Silver/Gold tier system across 51 files (~4950 lines removed).
Replace with flat isEligible boolean, update dynamic PR threshold from 500
to 300, revamp onboard Getting Started with 7-step inline setup guide
matching docs, remove Roadmap and FAQ tabs from onboard page.

🤖 Automated formatting by GitHub Actions

…ting

Replace dangerouslySetInnerHTML with ReactMarkdown + rehypeRaw for safe
rendering of GitHub-provided HTML in issue bodies and PR conversations.
Add missing CSS for lists, paragraphs, tables, and other elements that
MUI CssBaseline resets.

- Use ReactMarkdown with remarkGfm and rehypeRaw (same as ReadmeViewer)
- Add styles for ul/ol, li, p, table, hr, task checkboxes
- Fix pre/code nesting so inline code inside blocks renders correctly
- Left-align conversation panels to match GitHub layout
- Fix fallback text rendering (HTML em instead of markdown asterisks)

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>