WAS: Controller Integration APIs

### Enhancement Description - One-line enhancement description (can be used as a release note): Provide standard API building blocks, shared libraries, and guidelines enabling workload controllers to design native APIs for consuming Workload-Aware Scheduling (WAS) features. - Kubernetes Enhancement Proposal: TODO <!-- link to kubernetes/enhancements file; if none yet, link to PR --> - Discussion Link: - Initial Design Document: https://docs.google.com/document/d/1VG7Zto9JYuPG4Anb01WMRryJlfV6met0jgob3T2NjZ4/edit?tab=t.0#heading=h.3s8c0yl3azl9 - Discussed during WAS integration sync meeting on March 2nd, 2026: https://docs.google.com/document/d/1XSPdK4L3zkAFhAZ3hBQJr2k7JX9CpGD7NeQfujM1PT4/edit?tab=t.0#bookmark=id.nqpz70rt46z - PRs by stage and milestone: - [ ] Alpha - v1.37 - [ ] KEP (`k/enhancements`) update PR(s): - [ ] Code (`k/k`) update PR(s): - [ ] Docs (`k/website`) update PR(s): <!-- Uncomment these as you prepare the enhancement for the next stage - [ ] Beta - v1.xx - [ ] KEP (`k/enhancements`) update PR(s): - [ ] Code (`k/k`) update PR(s): - [ ] Docs (`k/website`) update(s): - [ ] Stable - v1.xx - [ ] KEP (`k/enhancements`) update PR(s): - [ ] Code (`k/k`) update PR(s): - [ ] Docs (`k/website`) update(s): --> _Please keep this description up to date. This will help the Enhancement Team to track the evolution of the enhancement efficiently._ /sig scheduling /area workload-aware-scheduling