semi implemented and features implemented save checkpoint

docs/features/unchecked/binaryindex/vulnerable-code-fingerprint-matching.md

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+# Vulnerable Code Fingerprint Matching (CFG + Basic Block + String Refs Ensemble)
+
+## Module
+BinaryIndex
+
+## Status
+IMPLEMENTED
+
+## Description
+Function-level vulnerability detection independent of package metadata using an ensemble of fingerprint algorithms: basic block hashing, control flow graph fingerprinting, and string reference fingerprinting. Combined generator provides multi-algorithm similarity matching with configurable thresholds. Includes pre-seeded fingerprints for high-impact CVEs in OpenSSL, glibc, zlib, and curl.
+
+## Implementation Details
+- **Modules**: `src/BinaryIndex/__Libraries/StellaOps.BinaryIndex.Analysis/`, `src/BinaryIndex/__Libraries/StellaOps.BinaryIndex.Ensemble/`, `src/BinaryIndex/__Libraries/StellaOps.BinaryIndex.Persistence/`
+- **Key Classes**:
+  - `SignatureMatcher` (`src/BinaryIndex/__Libraries/StellaOps.BinaryIndex.Analysis/SignatureMatcher.cs`) - matches vulnerability signatures using fingerprint index
+  - `EnsembleDecisionEngine` (`src/BinaryIndex/__Libraries/StellaOps.BinaryIndex.Ensemble/EnsembleDecisionEngine.cs`) - combines CFG, basic block, string ref, and ML embedding fingerprints with configurable weights
+  - `FunctionAnalysisBuilder` (`src/BinaryIndex/__Libraries/StellaOps.BinaryIndex.Ensemble/FunctionAnalysisBuilder.cs`) - assembles multi-algorithm fingerprint inputs
+  - `SemanticFingerprintGenerator` (`src/BinaryIndex/__Libraries/StellaOps.BinaryIndex.Semantic/SemanticFingerprintGenerator.cs`) - KSG-based semantic fingerprinting
+  - `CallNgramGenerator` (`src/BinaryIndex/__Libraries/StellaOps.BinaryIndex.Semantic/CallNgramGenerator.cs`) - call-sequence fingerprinting
+  - `BinaryVulnerabilityService` (`src/BinaryIndex/__Libraries/StellaOps.BinaryIndex.Persistence/Services/BinaryVulnerabilityService.cs`) - vulnerability lookup with pre-seeded fingerprints
+- **Models**: `SignatureIndexModels` (`src/BinaryIndex/__Libraries/StellaOps.BinaryIndex.Analysis/Models/`) - fingerprint index models
+- **Source**: SPRINT_20251226_013_BINIDX_fingerprint_factory.md
+
+## E2E Test Plan
+- [ ] Match a known vulnerable function (e.g., OpenSSL Heartbleed) against pre-seeded fingerprints and verify detection
+- [ ] Verify multi-algorithm ensemble: CFG fingerprint + basic block hash + string refs all contribute to match score
+- [ ] Verify configurable threshold: adjust threshold to 0.8 and verify borderline matches are excluded
+- [ ] Verify pre-seeded fingerprints exist for high-impact CVEs (OpenSSL, glibc, zlib, curl)
+- [ ] Verify false positive rate: submit clean binary functions and verify no false matches
+- [ ] Verify `EnsembleDecisionEngine` weight tuning affects match outcomes