openspec: finalize performance-teaching-hardening change

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: LessUp

openspec/changes/performance-teaching-hardening/design.md

@@ -71,9 +71,11 @@ graph TD
 | `examples/04-simd-vectorization/src/dispatch_example_main.cpp` | New: `dispatch_example` executable entry point |
 | `examples/04-simd-vectorization/CMakeLists.txt` | Extend: add `simd_dispatch` STATIC library target and `dispatch_example` executable target |
 | `tests/unit/simd/simd_dispatch_test.cpp` | New: correctness test for `dispatch_add_arrays` |
+| `tests/unit/simd/CMakeLists.txt` | Extend: wire `simd_dispatch_test` into the existing test target list |
 | `examples/04-simd-vectorization/README.md` | Extend: vectorization diagnostics section |
 | `docs/en/guides/learning-path.md` | Extend: vectorization diagnostics, sanitizer cross-link |
 | `docs/en/guides/validation.md` | New: sanitizer preset workflow (asan/tsan/ubsan) |
+| `docs/.vitepress/config.ts` | Extend: add English nav/sidebar entry for `docs/en/guides/validation.md` so the new page is reachable from the site; zh navigation is out of scope for this change |
 | `README.md` | Extend: cross-link to sanitizer docs |
 | `scripts/compare_benchmarks.py` | New: benchmark regression comparison script |
 | `benchmarks/README.md` | New: capture-and-compare workflow section |

openspec/changes/performance-teaching-hardening/specs/simd-vectorization/spec.md

@@ -4,6 +4,8 @@
 
 ### Requirement: Runtime CPU Dispatch
 
+> **Scope note**: This requirement adds *function-level runtime dispatch* for a single binary (selecting AVX2, SSE2, or scalar at call time via `__builtin_cpu_supports`). It extends the existing compile-time CPU capability / build-system requirement already covered by this module; it does not replace it. The compile-time path (e.g., `-mavx2` flag, CMake feature detection) remains in effect for all other targets.
+
 THE Example_Module SHALL provide a runtime CPU dispatch example that selects the highest-available SIMD instruction set at runtime.
 
 #### Scenario: Runtime dispatch selects correct path

openspec/changes/performance-teaching-hardening/tasks.md

@@ -15,7 +15,7 @@
 
 ## 3. Sanitizer workflow documentation
 
-- [ ] 3.1 Add `docs/en/guides/validation.md` documenting the `asan`, `tsan`, and `ubsan` presets with copy-pasteable commands; add entry to VitePress nav
+- [ ] 3.1 Add `docs/en/guides/validation.md` documenting the `asan`, `tsan`, and `ubsan` presets with copy-pasteable commands; update `docs/.vitepress/config.ts` to add an English nav/sidebar entry for the new page so it is reachable from the site (zh navigation is out of scope)
 - [ ] 3.2 Cross-link the sanitizer section from the root `README.md` quick-start
 
 ## 4. Benchmark regression comparison