# Policy Simulation Reachability Overrides

## Module
Cli

## Status
VERIFIED

## Description
What-if reachability overrides in policy simulation: override reachability states (reachable/unreachable) and scores for specific vulnerabilities or packages to model hypothetical scenarios.

## Implementation Details
- **Command Group**: `src/Cli/StellaOps.Cli/Commands/PolicyCommandGroup.cs` -- policy simulation commands
- **Commands**:
  - `stella policy simulate <file> --override-reachability <cve>=reachable|unreachable` -- override reachability state
  - `stella policy simulate <file> --override-score <cve>=<score>` -- override reachability score
- **What-if engine**: Applies overrides before evaluation to model hypothetical scenarios

## E2E Test Plan
- [ ] Run `stella policy simulate ./policy.stella --override-reachability CVE-2024-1234=unreachable` and verify override applied
- [ ] Run with `--override-score CVE-2024-1234=0.1` and verify score override
- [ ] Verify simulation results differ from baseline when overrides change gate outcomes
- [ ] Verify multiple overrides can be specified simultaneously
- [ ] Verify `--format json` output includes override annotations

## Verification

- **Verified**: 2026-02-13T15:30:00Z
- **Tier 0 (Source)**: pass -- all referenced source files exist on disk
- **Tier 1 (Build)**: pass -- module builds cleanly, 412 tests pass in StellaOps.Cli.Commands.Tests
- **Tier 2d (Integration)**: pass -- targeted integration tests confirm behavioral correctness
- **Test Project**: `src/Cli/__Tests/StellaOps.Cli.Commands.Tests/StellaOps.Cli.Commands.Tests.csproj`
- **Evidence**: `docs/qa/feature-checks/runs/cli/policy-simulation-reachability-overrides/run-001/tier2-integration-check.json`