feat: add analysis state and base

phases/analysis-state-analysis-base/step0.md

@@ -0,0 +1,62 @@
+# Step 0: analysis-contract-plan
+
+## Read First
+
+Read these files before editing:
+
+- `/AGENTS.md`
+- `/docs/PLAN.md`
+- `/docs/PROGRESS.md`
+- `/docs/WORKNOTE.md`
+- `/docs/AGENT_RULES.md`
+- `/docs/PRD.md`
+- `/docs/ADR.md`
+- `/docs/ARCHITECTURE.md`
+- `/docs/implementation-plans/analysis-model-objects-implementation-plan.md`
+- `/docs/implementation-plans/property-model-foundation-implementation-plan.md`
+- `/include/fesa/core/Domain.hpp`
+- `/include/fesa/core/ModelTypes.hpp`
+- `/include/fesa/core/StepDefinition.hpp`
+- `/CMakeLists.txt`
+
+## Task
+
+Create `/docs/implementation-plans/analysis-state-analysis-base-implementation-plan.md`.
+
+The document must define the implementation contract for:
+
+- `fesa::core::AnalysisState` as mutable analysis state storage.
+- `fesa::analysis::Analysis` as the base analysis strategy interface.
+- A dedicated CTest path for analysis-layer tests.
+
+State explicitly that this phase does not implement:
+
+- `AnalysisModel`
+- `DofManager`
+- MITC4 stiffness, stress, resultants, or force recovery
+- global assembly
+- constrained DOF elimination
+- MKL/PARDISO solve
+- HDF5 result writing beyond existing skeletons
+- reference comparison
+- Abaqus/Nastran/reference-solver execution
+
+## Tests To Write First
+
+This is a documentation planning step. Do not write C++ production code in this step.
+
+## Acceptance Criteria
+
+Run:
+
+```powershell
+python -m unittest discover -s scripts -p "test_*.py"
+python scripts/validate_workspace.py
+```
+
+Update `/phases/analysis-state-analysis-base/index.json` step 0 with `completed`, `error`, or `blocked`.
+
+## Do Not
+
+- Do not change C++ code in this step.
+- Do not change requirements, formulations, I/O contracts, reference artifacts, or tolerance policy.