[Domain] add recommended scenario drafts

[SilverSupplier]

Summary

• Adds domain-backed recommendation candidate generation for reviewable Recommended scenario drafts.
• Adds batch-result recommendation cards with evidence, artifact source, and expected improvement direction.
• Preserves Recommended role, provenance, diff keys, unstaged state, and control changes through authoring and persistence.
• Adds supporting recommendation evidence docs and keeps the branch diff whitespace-clean.

Related Issue

• Refs Task-persisted 결과 아티팩트 기반 운영 대안 후보 추천 구현 #84
• Refs Task-추천안을 ScenarioVariation으로 생성하고 근거 비교 지원 구현 #85
• Refs Task-추천 최적화 로직 조사 #107
• Does not auto-close these issues because they are shared recommendation planning/reference issues.

Area

• Engine
• Domain
• Application
• Docs
• Build
• Analysis
• Chore

Architecture Check

• I kept the dependency direction application -> domain -> engine.
• I did not add Qt UI code to src/domain.
• I did not add domain or application dependencies to src/engine.
• I used src/ as the include root.

Verification

• cmake --preset windows-debug (not run as a separate command; build preset reconfigured the existing tree)
• cmake --build --preset build-no-app-debug
• ctest --preset test-no-app-debug
• cmake --build --preset build-debug
• ctest --preset test-debug
• git diff --check origin/codex/two-floor-demo-project...HEAD
• Not run (reason below)

Risks / Follow-up

• V1 creates reviewable drafts only; it does not auto-stage, auto-run, rerun, batch-run, or optimize.
• Recommendations are conservative rule-based candidates and still require user review plus rerun validation.
• Blocked-connection relief now requires bottleneck evidence on the same blocked connection.