save checkpoint. addition features and their state. check some ofthem

docs/features/checked/tools/golden-pairs-validation-infrastructure.md

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+# Golden Pairs Validation Infrastructure
+
+## Module
+Tools
+
+## Status
+VERIFIED
+
+## Description
+Data model for golden pair metadata, binary artifacts, and diff reports used to validate binary diff detection against known-good CVE fix pairs.
+
+## Implementation Details
+- **Golden Pairs Models**: `src/Tools/GoldenPairs/Models/` (4 files, ~170 lines) -- `GoldenPairMetadata` (CVE ID, package name, distro, pre/post versions, binary artifacts with section hashes), `GoldenDiffReport` (sections, verdict, confidence, discrepancies), `SectionHashModels` (SectionHashSet, SectionHashEntry with Size), `GoldenPairsIndex` (version, pairs, summary).
+- **Golden Pairs Schema Provider**: `src/Tools/GoldenPairs/Schema/GoldenPairsSchemaProvider.cs` (36 lines) -- lazy-loads JSON schemas for metadata and index validation.
+- **Golden Pair Loader**: `src/Tools/GoldenPairs/Services/GoldenPairLoader.cs` (211 lines) -- loads and validates golden pair records with JSON Schema enforcement before deserialization, normalization, and error collection.
+- **Serialization**: `src/Tools/GoldenPairs/Serialization/GoldenPairsJsonSerializer.cs` (78 lines) -- `DeterministicTypeInfoResolver` for alphabetical property ordering, ensuring deterministic output for hash comparison and attestation.
+- **Section Hash Provider**: `src/Tools/GoldenPairs/Services/SectionHashProvider.cs` (87 lines) -- deterministic per-section hash computation via `IElfSectionHashExtractor`, producing ordered `SectionHashSet`.
+
+## E2E Test Plan
+- [x] Load a golden pair record and verify all required fields are populated and valid
+- [x] Validate metadata against schema and verify it passes; corrupt a field and verify validation fails
+- [x] Serialize a golden pair record, deserialize it back, and verify round-trip fidelity
+- [x] Compute section hashes on two separate runs and verify determinism
+- [x] Load a diff report and verify it correctly identifies changed sections
+- [x] Verify schema provider covers metadata and index schemas
+
+## Verification
+- **Verified**: 2026-02-10
+- **Method**: Tier 1 code review + Tier 2d test verification
+- **Build**: Passes (0 errors, 0 warnings)
+- **Tests**: 9 tests pass (shared with Golden Pairs Mirror feature: GoldenPairSchemaTests: 3, GoldenPairLoaderTests: 2, DiffPipelineServiceTests: 2, PackageMirrorServiceTests: 2)