Add MergeUsageAnalyzer to detect legacy merge service usage

- Implemented MergeUsageAnalyzer to flag usage of AdvisoryMergeService and AddMergeModule.
- Created AnalyzerReleases.Shipped.md and AnalyzerReleases.Unshipped.md for release documentation.
- Added tests for MergeUsageAnalyzer to ensure correct diagnostics for various scenarios.
- Updated project files for analyzers and tests to include necessary dependencies and configurations.
- Introduced a sample report structure for scanner output.

src/Scanner/__Tests/StellaOps.Scanner.WebService.Tests/SurfaceCacheOptionsConfiguratorTests.cs

@@ -19,12 +19,12 @@ public sealed class SurfaceCacheOptionsConfiguratorTests
             "surface-cache",
             null,
             cacheRoot,
-            cacheQuotaMegabytes: 512,
-            prefetchEnabled: true,
-            featureFlags: Array.Empty<string>(),
-            secrets: new SurfaceSecretsConfiguration("file", "tenant-b", "/etc/secrets", null, null, allowInline: false),
-            tenant: "tenant-b",
-            tls: new SurfaceTlsConfiguration(null, null, new X509Certificate2Collection()));
+            512,
+            true,
+            Array.Empty<string>(),
+            new SurfaceSecretsConfiguration("file", "tenant-b", "/etc/secrets", null, null, false),
+            "tenant-b",
+            new SurfaceTlsConfiguration(null, null, new X509Certificate2Collection()));
 
         var environment = new StubSurfaceEnvironment(settings);
         var configurator = new SurfaceCacheOptionsConfigurator(environment);