semi implemented and features implemented save checkpoint

docs/features/unchecked/libraries/policy-lock-generator.md

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+# Policy Lock Generator (Verdict Reproducibility)
+
+## Module
+__Libraries
+
+## Status
+IMPLEMENTED
+
+## Description
+Generates deterministic policy lock files that pin the exact policy rules, versions, and evaluation parameters used to produce a verdict. Ensures verdicts can be reproduced identically by capturing the full policy context alongside the CGS hash.
+
+## Implementation Details
+- **PolicyLockGenerator**: `src/__Libraries/StellaOps.Verdict/PolicyLockGenerator.cs` -- implements `IPolicyLockGenerator`; `GenerateAsync(policyId)` creates `PolicyLock` with SchemaVersion "1.0", auto-generated PolicyVersion from ID + timestamp, rule hashes dict, EngineVersion "1.0.0"; `GenerateForVersionAsync(policyId, version)` pins specific version; `ValidateAsync(policyLock)` checks SchemaVersion, PolicyVersion, EngineVersion, non-empty RuleHashes, future timestamp detection (5min tolerance), hash format validation ("sha256:" + 64 hex chars); `ComputeRuleHash` uses SHA256 of canonical JSON `{definition, version}` with prefix "sha256:"; uses injected `TimeProvider` for deterministic timestamps
+- **IPolicyLockGenerator**: `src/__Libraries/StellaOps.Verdict/IPolicyLockGenerator.cs` -- interface: GenerateAsync, GenerateForVersionAsync, ValidateAsync
+- **PolicyLock**: record with SchemaVersion, PolicyVersion, RuleHashes (IReadOnlyDictionary<string, string>), EngineVersion, GeneratedAt
+- **PolicyLockValidation**: record with IsValid, ErrorMessage, MismatchedRules
+- **VerdictBuilderService**: `src/__Libraries/StellaOps.Verdict/VerdictBuilderService.cs` -- integrates with PolicyLockGenerator
+- **VerdictServiceCollectionExtensions**: `src/__Libraries/StellaOps.Verdict/VerdictServiceCollectionExtensions.cs` -- DI registration
+- **Source**: SPRINT_20251229_001_001_BE_cgs_infrastructure.md
+
+## E2E Test Plan
+- [ ] Verify GenerateAsync creates PolicyLock with non-empty RuleHashes dictionary
+- [ ] Test ComputeRuleHash produces deterministic SHA-256 hash in "sha256:{hex}" format
+- [ ] Verify ValidateAsync detects missing required fields (SchemaVersion, PolicyVersion, EngineVersion)
+- [ ] Test future timestamp detection (GeneratedAt > now + 5 minutes fails validation)
+- [ ] Verify ValidateAsync catches invalid hash format (non-hex, wrong length)
+- [ ] Test GenerateForVersionAsync pins exact version string in PolicyLock
+- [ ] Verify same policy input produces identical PolicyLock (deterministic)
+- [ ] Test TimeProvider injection enables deterministic timestamp generation in tests