semi implemented and features implemented save checkpoint

docs/features/unchecked/binaryindex/function-range-hashing-and-symbol-mapping.md

@@ -0,0 +1,29 @@
+# Function-Range Hashing and Symbol Mapping
+
+## Module
+BinaryIndex
+
+## Status
+IMPLEMENTED
+
+## Description
+Multi-backend disassembly (Iced, B2R2) with function-range normalization for symbol-level binary proof.
+
+## Implementation Details
+- **Modules**: `src/BinaryIndex/__Libraries/StellaOps.BinaryIndex.Builders/`, `src/BinaryIndex/__Libraries/StellaOps.BinaryIndex.Diff/`
+- **Key Classes**:
+  - `IFunctionFingerprintExtractor` (`src/BinaryIndex/__Libraries/StellaOps.BinaryIndex.Builders/IFunctionFingerprintExtractor.cs`) - extracts function-range fingerprints from disassembled binaries
+  - `FunctionDiffer` (`src/BinaryIndex/__Libraries/StellaOps.BinaryIndex.Diff/FunctionDiffer.cs`) - compares function fingerprints with semantic analysis support; computes call-graph edge diffs
+  - `FunctionRenameDetector` (`src/BinaryIndex/__Libraries/StellaOps.BinaryIndex.Diff/FunctionRenameDetector.cs`) - detects renamed functions by comparing fingerprint similarity
+  - `PatchDiffEngine` (`src/BinaryIndex/__Libraries/StellaOps.BinaryIndex.Builders/PatchDiffEngine.cs`) - builder-level patch diff engine
+  - `FingerprintClaimModels` (`src/BinaryIndex/__Libraries/StellaOps.BinaryIndex.Builders/FingerprintClaimModels.cs`) - `FingerprintClaim` and `FingerprintClaimEvidence` records
+- **Models**: `FingerprintModels` (`src/BinaryIndex/__Libraries/StellaOps.BinaryIndex.Analysis/Models/FingerprintModels.cs`) - `FunctionFingerprint` with hash, size, call edges
+- **Disassembly Backends**: `B2R2DisassemblyPlugin` (ARM/x86/x64/AArch64), `IcedDisassemblyPlugin` (x86/x64)
+
+## E2E Test Plan
+- [ ] Extract function fingerprints from an ELF binary and verify hash consistency for identical functions
+- [ ] Verify function-range normalization produces same hash across compiler optimization levels when function logic is identical
+- [ ] Verify `FunctionDiffer` correctly identifies added, removed, and modified functions
+- [ ] Verify `FunctionRenameDetector` matches renamed functions based on fingerprint similarity threshold
+- [ ] Verify `FingerprintClaim` evidence links correctly to Build-ID and function IDs
+- [ ] Verify multi-backend consistency: same binary produces matching fingerprints via B2R2 and Iced