chore: upgrade eve to 1.0.0-rc.0

Why

Upgrade this gallery template to Eve 1.0.0-rc.0.

Gallery: https://vercel.com/templates/eve/eve-github-maintainer

Necessary migrations

• Regenerated the lockfile for Eve 1.0.0-rc.0.
• Renamed compaction.thresholdPercent to threshold without changing the 0.75 threshold.
• Migrated root instructions and the weekly schedule from markdown to content, preserving their prompts and scheduling behavior.

Validation

• Passed: pnpm install, pnpm typecheck, and pnpm check.
• Ran pnpm validate, eve info, and eve build --skip-sandbox-prewarm with harmless placeholder configuration.

Blocker

@github-tools/eve-extension@0.9.0 is the only published release and was built against Eve 0.81. Eve 1.0.0-rc.0 rejects its old epoch-based distribution manifest. There is no compatible published extension release or tag, so discovery and build retain one real error. The extension remains in place because it provides the GitHub maintainer tools and their configured approval boundary.

No live model evaluations or external service actions were run.