test(enterprise): verify D10 RAM admission

[Gracker]

Summary

• add D10 to the enterprise multi-window regression script
• verify RAM admission rejects a new lease near budget without creating candidate lease rows
• verify the existing active frontend lease, trace asset, and file remain intact, and same-trace shared holders can reuse the existing lease
• mark README §0.7 D10 complete

Base

• Stacked on test(enterprise): verify D9 restart recovery #107 / feature/enterprise-multi-tenant-d9-restart-recovery

Verification

• cd backend && npx jest --runInBand --forceExit src/scripts/tests/verifyEnterpriseMultiTenantWindows.test.ts
• cd backend && npx jest --runInBand --forceExit src/services/tests/traceProcessorRamBudget.test.ts src/services/tests/workingTraceProcessor.enterpriseIsolation.test.ts
• cd backend && npm run typecheck
• git diff --check
• npm run verify:pr

[Gracker]

已通过 commit 67856ec (merge) + 023a84a (frontend rebuild) 合入 main，关闭此 PR。