# Sprint Contract: Assembly Analysis Extraction

## Objective
Move full-space assembly, reduced projection, reaction recovery path, analysis state/result objects, and linear static workflow into `Assembly` and `Analysis` while preserving Phase 1 solver behavior.

## Required Reading
- /AGENTS.md
- /PROGRESS.md
- /PLAN.md
- /docs/README.md
- /docs/HARNESS_ENGINEERING.md
- /docs/ARCHITECTURE.md
- /docs/ADR.md
- /docs/NUMERICAL_CONVENTIONS.md
- /docs/RESULTS_SCHEMA.md
- /docs/MITC4_FORMULATION.md
- /docs/VERIFICATION_PLAN.md
- /phases/1-structure-alignment-refactor/step0-architecture-map.md
- /phases/1-structure-alignment-refactor/step2.md
- /phases/1-structure-alignment-refactor/step3.md
- /phases/1-structure-alignment-refactor/step5.md
- /phases/1-structure-alignment-refactor/step7.md

## Scope
- Extract `AssemblyResult`, `ReducedSystem`, full-space assembly, reduced projection, and full-vector reaction recovery helpers into `Assembly`.
- Extract `AnalysisState`, `AnalysisResult`, `Analysis`, `LinearStaticAnalysis`, and input-to-analysis convenience workflow into `Analysis`.
- Keep Strategy + Template Method structure visible.
- Preserve `RF = K_full * U_full - F_full`.
- Preserve solver adapter injection and deterministic default solver behavior.

## Allowed Files
- `include/fesa/fesa.hpp`
- `include/fesa/Assembly/`
- `src/Assembly/`
- `include/fesa/Analysis/`
- `src/Analysis/`
- `include/fesa/Core/`
- `include/fesa/Element/`
- `include/fesa/Math/`
- `include/fesa/Results/`
- `include/fesa/IO/`
- `tests/`
- `CMakeLists.txt`
- `phases/1-structure-alignment-refactor/index.json`
- `PLAN.md`
- `PROGRESS.md`

## Explicit Non-Goals
- Do not change solve algorithms, convergence logic, boundary-condition semantics, or result schema.
- Do not add nonlinear, dynamic, heat-transfer, pressure-load, RBE, or HDF5 behavior.
- Do not compute reactions from reduced quantities.
- Do not add production sparse storage beyond the existing scaffold.

## Tests To Write First
- Add or update include/link tests for `Assembly` and `Analysis` module headers.
- Preserve assembly, reduced solve, solver injection, full-vector RF, input-to-result workflow, and `quad_02_phase1` reference regression tests as characterization tests.

## Reference Artifacts
- `references/quad_02_phase1.inp`
- `references/quad_02_displacements.csv`

Do not edit these files.

## Acceptance Commands
```bash
python scripts/validate_workspace.py
```

## Evaluator Checklist
- Assembly owns full-space stiffness/load preservation and reduced projection.
- Analysis owns execution flow and state updates.
- `DofManager` remains the owner of equation numbering and full/reduced mapping.
- Full-vector RF recovery is unchanged.
- `quad_02_phase1` displacement regression still passes.

## Handoff Requirements
- Update this step status in `phases/1-structure-alignment-refactor/index.json`.
- Record moved assembly/analysis files and any remaining production implementation still left in `fesa.hpp`.

## Do Not
- Do not hide a behavior change under the label "refactor".
- Do not broaden Phase 1 feature scope.