feat(rate): add React Morris screening workflow

[d-sorgcodexagent]

Summary

• add the independently reviewed React Morris elementary-effects workflow alongside unchanged Monte Carlo variation
• inject the same-origin authority client and preserve exact request/job lifecycle identity, bounded operations, cancellation, and stale-evidence invalidation
• align normally on current PyQt child PR feat(rate): add PyQt Morris screening workflow #4400 and inherit its protected-CI formatting/file-size repairs

Stack

• base: codex/4142-morris-pyqt-workflow / PR feat(rate): add PyQt Morris screening workflow #4400 exact head 9e62c9595ccfbcf7eaa14724ad7e6d65d5277cee
• head: codex/4142-morris-react-integration exact head 37fe8d33bdb4ce26465f478757dfd7f081c04372
• reviewed React commit: eedfc24a163af736caa47c4f0c74912a7f165036
• merge only after protected parents land in order

Validation

• Python Rate suite: 913 passed serial
• focused PyQt Morris/Variation: 151 passed
• Ruff check/format, MyPy, changed-file and module-size gates: passed
• React full: 100 files / 705 tests passed
• React focused Morris: 6 files / 129 tests passed
• TypeScript typecheck, zero-warning ESLint, production Vite build: passed
• minimum Python contract: 2 passed
• independent exact-head integration audit: GO, no findings

Open gates

• Morris workspace persistence/export is a separate lossless child slice
• UpstreamDrift replacement consumer remains open
• protected exact-head CI and dependency-ordered merge remain required
• this PR does not complete epic Epic: Ensemble variation, swing quiet zones, and sensitivity attribution #4142