[fix] Reject inverted budget ranges in job validation (#2853)

[xiaofengzii]

Summary

This PR fixes the issue where createJobSchema accepts payloads where �udgetMax is lower than �udgetMin, creating invalid job records.

Changes

1. Modified �pps/api/src/validators/job.js:

   • Added .refine() to createJobSchema to validate that �udgetMax >= budgetMin
   • Created a separate updateJobSchema (instead of using .partial()) with the same validation logic that only checks when both fields are present

2. Added �pps/api/src/tests/job.test.js:

   • Comprehensive test coverage for budget validation
   • Tests for rejection of inverted ranges
   • Tests for acceptance of valid ranges
   • Tests for equal budgetMin and budgetMax
   • Tests for partial update scenarios

Verification

All tests pass:

• createJobSchema rejects inverted budget ranges (budgetMax < budgetMin)
• createJobSchema accepts valid budget ranges (budgetMax >= budgetMin)
• createJobSchema accepts equal budgetMin and budgetMax
• updateJobSchema rejects inverted budget ranges when both are present
• updateJobSchema accepts valid budget ranges
• updateJobSchema accepts single budget field

Related Issues

• Fixes Job validation should reject inverted budget ranges #2853
• Related to parent bounty Low Handing Fruit Automation #743