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/Concelier/__Libraries/StellaOps.Concelier.Storage.Mongo/Observations/AdvisoryObservationStore.cs

@@ -1,11 +1,13 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using MongoDB.Driver;
-using StellaOps.Concelier.Core.Observations;
-using StellaOps.Concelier.Models.Observations;
-
-namespace StellaOps.Concelier.Storage.Mongo.Observations;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text.RegularExpressions;
+using MongoDB.Bson;
+using MongoDB.Driver;
+using StellaOps.Concelier.Core.Observations;
+using StellaOps.Concelier.Models.Observations;
+
+namespace StellaOps.Concelier.Storage.Mongo.Observations;
 
 internal sealed class AdvisoryObservationStore : IAdvisoryObservationStore
 {
@@ -48,31 +50,35 @@ internal sealed class AdvisoryObservationStore : IAdvisoryObservationStore
         }
         cancellationToken.ThrowIfCancellationRequested();
 
-        var normalizedTenant = tenant.ToLowerInvariant();
-        var normalizedObservationIds = NormalizeValues(observationIds, static value => value);
-        var normalizedAliases = NormalizeValues(aliases, static value => value.ToLowerInvariant());
-        var normalizedPurls = NormalizeValues(purls, static value => value);
-        var normalizedCpes = NormalizeValues(cpes, static value => value);
-
-        var builder = Builders<AdvisoryObservationDocument>.Filter;
-        var filters = new List<FilterDefinition<AdvisoryObservationDocument>>
-        {
-            builder.Eq(document => document.Tenant, normalizedTenant)
+        var normalizedTenant = tenant.ToLowerInvariant();
+        var normalizedObservationIds = NormalizeValues(observationIds, static value => value);
+        var normalizedAliases = NormalizeAliasFilters(aliases);
+        var normalizedPurls = NormalizeValues(purls, static value => value);
+        var normalizedCpes = NormalizeValues(cpes, static value => value);
+
+        var builder = Builders<AdvisoryObservationDocument>.Filter;
+        var filters = new List<FilterDefinition<AdvisoryObservationDocument>>
+        {
+            builder.Eq(document => document.Tenant, normalizedTenant)
         };
 
         if (normalizedObservationIds.Length > 0)
         {
             filters.Add(builder.In(document => document.Id, normalizedObservationIds));
         }
-
-        if (normalizedAliases.Length > 0)
-        {
-            filters.Add(builder.In("linkset.aliases", normalizedAliases));
-        }
-
-        if (normalizedPurls.Length > 0)
-        {
-            filters.Add(builder.In("linkset.purls", normalizedPurls));
+
+        if (normalizedAliases.Length > 0)
+        {
+            var aliasFilters = normalizedAliases
+                .Select(alias => CreateAliasFilter(builder, alias))
+                .ToList();
+
+            filters.Add(builder.Or(aliasFilters));
+        }
+
+        if (normalizedPurls.Length > 0)
+        {
+            filters.Add(builder.In("linkset.purls", normalizedPurls));
         }
 
         if (normalizedCpes.Length > 0)
@@ -101,16 +107,16 @@ internal sealed class AdvisoryObservationStore : IAdvisoryObservationStore
             .Limit(limit)
             .ToListAsync(cancellationToken)
             .ConfigureAwait(false);
-
-        return documents.Select(AdvisoryObservationDocumentFactory.ToModel).ToArray();
-    }
-
-    private static string[] NormalizeValues(IEnumerable<string>? values, Func<string, string> projector)
-    {
-        if (values is null)
-        {
-            return Array.Empty<string>();
-        }
+
+        return documents.Select(AdvisoryObservationDocumentFactory.ToModel).ToArray();
+    }
+
+    private static string[] NormalizeValues(IEnumerable<string>? values, Func<string, string> projector)
+    {
+        if (values is null)
+        {
+            return Array.Empty<string>();
+        }
 
         var set = new HashSet<string>(StringComparer.Ordinal);
         foreach (var value in values)
@@ -131,7 +137,51 @@ internal sealed class AdvisoryObservationStore : IAdvisoryObservationStore
         {
             return Array.Empty<string>();
         }
-
-        return set.ToArray();
-    }
-}
+
+        return set.ToArray();
+    }
+
+    private static string[] NormalizeAliasFilters(IEnumerable<string>? aliases)
+    {
+        if (aliases is null)
+        {
+            return Array.Empty<string>();
+        }
+
+        var set = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+        var list = new List<string>();
+
+        foreach (var alias in aliases)
+        {
+            if (alias is null)
+            {
+                continue;
+            }
+
+            var trimmed = alias.Trim();
+            if (trimmed.Length == 0)
+            {
+                continue;
+            }
+
+            if (set.Add(trimmed))
+            {
+                list.Add(trimmed);
+            }
+        }
+
+        return list.Count == 0 ? Array.Empty<string>() : list.ToArray();
+    }
+
+    private static FilterDefinition<AdvisoryObservationDocument> CreateAliasFilter(
+        FilterDefinitionBuilder<AdvisoryObservationDocument> builder,
+        string alias)
+    {
+        var escaped = Regex.Escape(alias);
+        var regex = new BsonRegularExpression($"^{escaped}$", "i");
+
+        return builder.Or(
+            builder.Regex("rawLinkset.aliases", regex),
+            builder.Regex("linkset.aliases", regex));
+    }
+}