Add centralized bounty issue discovery page

[TerryFYL]

Summary

• replace the homepage with a centralized bounty issue discovery view
• move the previous deployment and operations guide to /deploy
• persist issue metadata from bounty-labeled GitHub issues for discovery cards

Testing

• npm run prisma:generate
• node --disable-warning=ExperimentalWarning --experimental-transform-types --test tests/*.test.ts
• node node_modules/typescript/bin/tsc --noEmit
• DATABASE_URL=postgresql://postgres:postgres@localhost:5432/pvium_github_app node node_modules/next/dist/bin/next build
• Browser smoke test: / and /deploy on localhost:3011

Note: the upstream lockfile appears to be out of sync with package.json, so dependency installation was performed with npm install --package-lock=false to avoid changing package-lock.json in this PR.

Closes #43

Disclosure: This PR was implemented with AI assistance and manually reviewed/tested before submission.

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