# Reproducible build verification

## Module
BinaryIndex

## Status
IMPLEMENTED

## Description
Reproducible build backend supports local rebuilds with air-gap bundle support for verifying binary provenance.

## Implementation Details
- **Modules**: `src/BinaryIndex/__Libraries/StellaOps.BinaryIndex.Builders/`, `src/BinaryIndex/StellaOps.BinaryIndex.Worker/`, `src/BinaryIndex/__Libraries/StellaOps.BinaryIndex.GroundTruth.Reproducible/`
- **Key Classes**:
  - `ReproducibleBuildJob` (`src/BinaryIndex/StellaOps.BinaryIndex.Worker/Jobs/ReproducibleBuildJob.cs`) - worker job that executes reproducible builds using `IFunctionFingerprintExtractor`, `IPatchDiffEngine`, and `IFingerprintClaimRepository`
  - `ReproducibleBuildJob` (builders) (`src/BinaryIndex/__Libraries/StellaOps.BinaryIndex.Builders/ReproducibleBuildJobTypes.cs`) - builder-level reproducible build job with options
  - `ReproducibleBuildOptions` - configuration for build verification parameters
  - `ValidationHarnessService` (`src/BinaryIndex/__Libraries/StellaOps.BinaryIndex.GroundTruth.Reproducible/ValidationHarnessService.cs`) - validates reproducible build outputs
  - `FingerprintClaim` / `FingerprintClaimEvidence` (`src/BinaryIndex/__Libraries/StellaOps.BinaryIndex.Builders/FingerprintClaimModels.cs`) - claims produced from build verification
- **Interfaces**: `IReproducibleBuilder` (`src/BinaryIndex/__Libraries/StellaOps.BinaryIndex.Builders/IReproducibleBuilder.cs`), `IReproducibleBuildJob`

## E2E Test Plan
- [ ] Submit a source package and verify reproducible build produces matching binary fingerprints
- [ ] Verify `FingerprintClaim` is generated with correct `FingerprintClaimEvidence` linking to Build-ID
- [ ] Verify build verification with non-matching binaries produces a failed verification result
- [ ] Verify air-gap bundle support: import build inputs from bundle and verify build completes offline
- [ ] Verify `ReproducibleBuildOptions` configuration controls build behavior
- [ ] Verify build job integrates with `IPatchDiffEngine` for post-build comparison