# Delta Scan CLI Command

## Module
Cli

## Status
VERIFIED

## Description
CLI command `stella scan delta --old <image> --new <image>` for delta scanning between container image versions. Supports JSON/text/summary output formats, exit codes for CVE status (0=clean, 1=new CVEs, 2=error), and flags for policy, platform, SBOM format, signing, Rekor submission, and timeout configuration.

## Implementation Details
- **Command Group**: `src/Cli/StellaOps.Cli/Commands/DeltaCommandGroup.cs` -- `DeltaCommandGroup` for `stella delta` / `stella scan delta` commands
- **Commands**:
  - `stella scan delta --old <image> --new <image>` -- delta scan between two image versions. Options: `--format json|text|summary`, `--policy <file>`, `--platform <arch>`, `--sbom-format cdx|spdx`, `--sign`, `--rekor`, `--timeout <duration>`
- **Exit codes**: 0=no new CVEs, 1=new CVEs found, 2=error
- **Integration**: Connects to Scanner module for diff computation

## E2E Test Plan
- [ ] Run `stella scan delta --old app:v1.0 --new app:v2.0` and verify delta scan results
- [ ] Run with `--format json` and verify structured delta output
- [ ] Run with `--format summary` and verify summary output
- [ ] Verify exit code 0 when no new CVEs introduced
- [ ] Verify exit code 1 when new CVEs found in new image
- [ ] Run with `--sign --rekor` and verify signed results with Rekor entry
- [ ] Run with `--policy ./policy.stella` and verify policy evaluation against delta
- [ ] Verify `--timeout` flag works for long-running scans

## 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/delta-scan-cli-command/run-001/tier2-integration-check.json`