Add bounty issue discovery homepage

[1507819106zxzx-crypto]

Summary

• replace the root page with a bounty issue discovery dashboard backed by stored Pvium bounty records
• add Recent Issues and Top Issues views with minimum bounty and sort order controls
• move the existing setup/deployment documentation page to /deploy

Closes #43.

Verification

• npm run typecheck
• npm test
• npm run build

[vercel]

@kukerzzz is attempting to deploy a commit to the Bytegum Team on Vercel.

A member of the Team first needs to authorize it.

[1507819106zxzx-crypto]

Local verification completed on this branch:

• npm run typecheck
• npm test
• npm run build

The current Vercel failure appears to be the external fork authorization gate from the Vercel bot comment, not a build failure from this change.