ROB-74: add durable job evaluation lifecycle

[robertn702]

Summary

Adds a durable, source-independent lifecycle for asynchronous job evaluations without blocking job ingestion or overloading the existing resume-match fields.

Changes

• add versioned JobEvaluation persistence and migration
• canonicalize current persisted job and default-resume inputs server-side
• add leased claim, fenced complete/fail, retry, and current/history access APIs
• add a least-privilege evaluations:worker token preset
• preserve existing Job.matchScore and Job.matchData behavior

Related Issues

Closes ROB-74
Closes #100

Testing

• npx prisma generate
• DATABASE_URL="file:/tmp/jobsync-rob74-verify.db" npx prisma migrate deploy
• npx tsc --noEmit
• npm run lint
• npm test -- --run src/lib/jobEvaluations/service.test.ts

This PR remains draft while the real-SQLite concurrency/auth/source integration matrix and final high-risk review are completed.