docs: align consolidated solver workflow

phases/linear-static-3d-euler-beam/step8.md

@@ -10,9 +10,9 @@
 - `/AGENTS.md`
 - `/docs/ARCHITECTURE.md`
 - `/docs/ADR.md`
-- `/docs/requirements/linear-static-3d-euler-beam.md`
-- `/docs/io-definitions/linear-static-3d-euler-beam-io.md`
-- `/docs/implementation-plans/linear-static-3d-euler-beam.md`
+- `/docs/linear-static-3d-euler-beam/requirements.md`
+- `/docs/linear-static-3d-euler-beam/io.md`
+- `/docs/linear-static-3d-euler-beam/implementation-plan.md`
 - `/include/fesa/build_info.hpp`
 - `/src/fesa/CMakeLists.txt`
 - `/tests/CMakeLists.txt`
@@ -97,7 +97,7 @@ deterministic ordering을 검증해야 한다.
 1. GoogleTest를 먼저 추가하고 targeted RED를 관찰한다.
 2. 최소 production 구현으로 targeted GREEN을 만든다.
 3. 전체 MSVC x64 Debug build/CTest VERIFY를 실행한다.
-4. `/docs/implementation-plans/linear-static-3d-euler-beam-implementation-report.md`의
+4. `/docs/linear-static-3d-euler-beam/implementation-report.md`의
    Step 8 section에 실제 RED/GREEN/VERIFY command, exit code, 핵심 output과 변경 파일을 기록한다.
 5. public header dependency를 검토하고 Step 8에 `completed`와 RED/GREEN/VERIFY 요약을 기록한다.