docs: align consolidated solver workflow

phases/linear-static-3d-euler-beam/step7.md

@@ -11,7 +11,7 @@
 - `/AGENTS.md`
 - `/docs/ARCHITECTURE.md`
 - `/docs/ADR.md`
-- `/docs/implementation-plans/linear-static-3d-euler-beam.md`
+- `/docs/linear-static-3d-euler-beam/implementation-plan.md`
 - `/docs/superpowers/specs/2026-08-08-linear-static-3d-euler-beam-design.md`
 - `/docs/HARNESS_WORKFLOW.md`
 - `/docs/HARNESS.md`
@@ -26,7 +26,7 @@
 - Create: `/src/fesa/CMakeLists.txt`
 - Create: `/tests/CMakeLists.txt`
 - Create: `/tests/unit/build_info_test.cpp`
-- Create: `/docs/implementation-plans/linear-static-3d-euler-beam-implementation-report.md`
+- Create: `/docs/linear-static-3d-euler-beam/implementation-report.md`
 
 ## 작업
 
@@ -44,7 +44,7 @@ MSVC x64 Debug에서 이후 모든 C++ step을 TDD로 실행할 최소 build/tes
 - `tests/CMakeLists.txt`, `tests/unit/build_info_test.cpp`: GoogleTest 연결,
   `gtest_discover_tests`, `BuildInfo` regex와 공통 `linear-static-3d-euler-beam` label을 가진
   최소 제품 test. 이후 이 phase의 모든 CTest는 같은 공통 label을 상속한다.
-- `docs/implementation-plans/linear-static-3d-euler-beam-implementation-report.md`:
+- `docs/linear-static-3d-euler-beam/implementation-report.md`:
   feature metadata, dependency/configure evidence와 Step 7–24별 RED/GREEN/VERIFY command,
   exit code, 핵심 output, 변경 파일, requirement/test trace를 누적할 implementation report.
 
@@ -77,7 +77,7 @@ ctest --test-dir .harness/build -C Debug -R BuildInfo --output-on-failure
 $discovery = ctest --test-dir .harness/build -C Debug --show-only=json-v1 | ConvertFrom-Json
 if ($discovery.tests.Count -lt 1) { throw 'CTest discovered zero tests' }
 ctest --test-dir .harness/build -C Debug --output-on-failure
-if (-not (Test-Path 'docs/implementation-plans/linear-static-3d-euler-beam-implementation-report.md')) {
+if (-not (Test-Path 'docs/linear-static-3d-euler-beam/implementation-report.md')) {
   throw 'Missing implementation evidence report'
 }
 ```