Add comprehensive tests for PathConfidenceScorer, PathEnumerator, ShellSymbolicExecutor, and SymbolicState

- Implemented unit tests for PathConfidenceScorer to evaluate path scoring under various conditions, including empty constraints, known and unknown constraints, environmental dependencies, and custom weights.
- Developed tests for PathEnumerator to ensure correct path enumeration from simple scripts, handling known environments, and respecting maximum paths and depth limits.
- Created tests for ShellSymbolicExecutor to validate execution of shell scripts, including handling of commands, branching, and environment tracking.
- Added tests for SymbolicState to verify state management, variable handling, constraint addition, and environment dependency collection.

src/__Libraries/__Tests/StellaOps.Cryptography.Tests/BouncyCastleEd25519CryptoProviderTests.cs

@@ -1,3 +1,4 @@
+using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using StellaOps.Cryptography;
 using StellaOps.Cryptography.DependencyInjection;
@@ -11,7 +12,9 @@ public sealed class BouncyCastleEd25519CryptoProviderTests
     [Fact]
     public async Task SignAndVerify_WithBouncyCastleProvider_Succeeds()
     {
+        var configuration = new ConfigurationBuilder().Build();
         var services = new ServiceCollection();
+        services.AddSingleton<IConfiguration>(configuration);
         services.AddStellaOpsCrypto();
         services.AddBouncyCastleEd25519Provider();