docs(phases): add harness self-test bootstrap step

docs/superpowers/plans/2026-07-29-fesa-phase-1.md

@@ -73,7 +73,7 @@ intentionally differs.
 
 | Order | Harness phase | Plan tasks | Independent deliverable |
 | ---: | --- | --- | --- |
-| 0 | `solver-bootstrap` | 1-2 | Reproducible C++20 build, dependency smoke tests, core IDs and diagnostics |
+| 0 | `solver-bootstrap` | Harness baseline, 1-2 | Harness self-tests, reproducible C++20 build, dependency smoke tests, core IDs and diagnostics |
 | 1 | `domain-and-input-skeleton` | 3-4 | Flat or single-Instance B31 input becomes an immutable normalized `Domain` |
 | 2 | `fem-and-beam-kernel` | 5-6 | Real Timoshenko Beam local stiffness with analytical sanity tests |
 | 3 | `equation-and-linear-solve` | 7-8 | Deterministic serial CSR system solved by PARDISO |
@@ -123,6 +123,9 @@ docs/VALIDATION.md                     benchmark matrix and qualification result
 
 **Files:**
 
+- Create before CMake bootstrap: `tests/harness/test_config.py`
+- Create before CMake bootstrap: `tests/harness/test_discovery.py`
+- Create before CMake bootstrap: `tests/harness/test_process.py`
 - Create: `CMakeLists.txt`
 - Create: `CMakePresets.json`
 - Create: `cmake/FesaDependencies.cmake`
@@ -141,6 +144,11 @@ docs/VALIDATION.md                     benchmark matrix and qualification result
 - Produces presets: `windows-debug`, `windows-release`
 - Later tasks consume the common warning and include-directory policies.
 
+Before the CMake task, add characterization tests for the existing Harness
+configuration, project discovery, and validation-result contracts. This
+precondition makes the repository-level pytest command collect at least one
+test without changing production Harness behavior.
+
 - [ ] **Step 1: Verify required installed packages without changing the machine**
 
 Run: