feat: Implement distro-native version comparison for RPM, Debian, and Alpine packages

- Add RpmVersionComparer for RPM version comparison with epoch, version, and release handling.
- Introduce DebianVersion for parsing Debian EVR (Epoch:Version-Release) strings.
- Create ApkVersion for parsing Alpine APK version strings with suffix support.
- Define IVersionComparator interface for version comparison with proof-line generation.
- Implement VersionComparisonResult struct to encapsulate comparison results and proof lines.
- Add tests for Debian and RPM version comparers to ensure correct functionality and edge case handling.
- Create project files for the version comparison library and its tests.

docs/implplan/SPRINT_4600_SUMMARY.md

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+# SPRINT_4600 SUMMARY: SBOM Lineage & BYOS Ingestion
+
+## Program Overview
+
+| Field | Value |
+|-------|-------|
+| **Program ID** | 4600 |
+| **Theme** | SBOM Operations: Historical Tracking, Lineage, and Ingestion |
+| **Priority** | P2 (Medium) |
+| **Total Effort** | ~5 weeks |
+| **Advisory Source** | 19-Dec-2025 - Stella Ops candidate features mapped to moat strength |
+
+---
+
+## Strategic Context
+
+SBOM storage is becoming table stakes. Differentiation comes from:
+1. **Lineage ledger** — Historical tracking with semantic diff
+2. **BYOS ingestion** — Accept external SBOMs into the analysis pipeline
+
+---
+
+## Sprint Breakdown
+
+| Sprint ID | Title | Effort | Moat |
+|-----------|-------|--------|------|
+| 4600_0001_0001 | SBOM Lineage Ledger | 3 weeks | 3 |
+| 4600_0001_0002 | BYOS Ingestion Workflow | 2 weeks | 3 |
+
+---
+
+## Dependencies
+
+- **Requires**: SbomService (exists)
+- **Requires**: Graph module (exists)
+- **Requires**: SPRINT_4600_0001_0001 for BYOS
+
+---
+
+## Outcomes
+
+1. SBOM versions are chained by artifact identity
+2. Historical queries and diffs are available
+3. External SBOMs can be uploaded and analyzed
+4. Lineage relationships are queryable
+
+---
+
+## Moat Strategy
+
+> "Make the ledger valuable via **semantic diff, evidence joins, and provenance** rather than storage."
+
+---
+
+**Sprint Series Status:** TODO
+
+**Created:** 2025-12-22