feat: Add DigestUpsertRequest and LockEntity models

- Introduced DigestUpsertRequest for handling digest upsert requests with properties like ChannelId, Recipient, DigestKey, Events, and CollectUntil.
- Created LockEntity to represent a lightweight distributed lock entry with properties such as Id, TenantId, Resource, Owner, ExpiresAt, and CreatedAt.

feat: Implement ILockRepository interface and LockRepository class

- Defined ILockRepository interface with methods for acquiring and releasing locks.
- Implemented LockRepository class with methods to try acquiring a lock and releasing it, using SQL for upsert operations.

feat: Add SurfaceManifestPointer record for manifest pointers

- Introduced SurfaceManifestPointer to represent a minimal pointer to a Surface.FS manifest associated with an image digest.

feat: Create PolicySimulationInputLock and related validation logic

- Added PolicySimulationInputLock record to describe policy simulation inputs and expected digests.
- Implemented validation logic for policy simulation inputs, including checks for digest drift and shadow mode requirements.

test: Add unit tests for ReplayVerificationService and ReplayVerifier

- Created ReplayVerificationServiceTests to validate the behavior of the ReplayVerificationService under various scenarios.
- Developed ReplayVerifierTests to ensure the correctness of the ReplayVerifier logic.

test: Implement PolicySimulationInputLockValidatorTests

- Added tests for PolicySimulationInputLockValidator to verify the validation logic against expected inputs and conditions.

chore: Add cosign key example and signing scripts

- Included a placeholder cosign key example for development purposes.
- Added a script for signing Signals artifacts using cosign with support for both v2 and v3.

chore: Create script for uploading evidence to the evidence locker

- Developed a script to upload evidence to the evidence locker, ensuring required environment variables are set.

src/Policy/__Tests/StellaOps.Policy.Engine.Tests/Console/ConsoleSimulationDiffServiceTests.cs

@@ -22,7 +22,7 @@ public sealed class ConsoleSimulationDiffServiceTests
                 new ConsoleArtifactScope("sha256:def", "pkg:npm/bar@2.0.0")
             },
             Filters: new ConsoleSimulationFilters(new[] { "high", "critical" }, new[] { "RULE-1234" }),
-            Budget: new ConsoleSimulationBudget(maxFindings: 10, maxExplainSamples: 5),
+            Budget: new ConsoleSimulationBudget(10, 5),
             EvaluationTimestamp: new DateTimeOffset(2025, 12, 2, 0, 0, 0, TimeSpan.Zero));
 
         var first = service.Compute(request);