docs: align consolidated solver workflow

phases/linear-static-3d-euler-beam/step9.md

@@ -10,8 +10,8 @@
 - `/AGENTS.md`
 - `/docs/ARCHITECTURE.md`
 - `/docs/ADR.md`
-- `/docs/requirements/linear-static-3d-euler-beam.md`
-- `/docs/implementation-plans/linear-static-3d-euler-beam.md`
+- `/docs/linear-static-3d-euler-beam/requirements.md`
+- `/docs/linear-static-3d-euler-beam/implementation-plan.md`
 - `/include/fesa/core/status.hpp`
 - `/src/fesa/CMakeLists.txt`
 - `/tests/CMakeLists.txt`
@@ -100,7 +100,7 @@ if ($LASTEXITCODE -ne 1) { throw 'Public-header dependency scan failed' }
 1. `vector_test.cpp`, `matrix_test.cpp`를 먼저 작성하고 missing behavior RED를 확인한다.
 2. 최소 adapter/ownership 구현으로 GREEN을 만든다.
 3. 전체 MSVC x64 Debug VERIFY와 public-header dependency scan을 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 9 section에 실제 RED/GREEN/VERIFY command, exit code,
    핵심 output과 변경 파일을 기록한다.
 5. Step 9를 `completed`로 바꾸고 operations/test evidence를 summary에 기록한다.