Suppress S2245 in benchmarks: document non-security fixed-seed Random usage

- Add NOSONAR:S2245 with justification above Random usages in benchmark/test projects (68 sites) - all use fixed seeds for reproducible benchmark data generation.

Verified: benchmark projects build with 0 errors.

Author: MPCoreDeveloper

tests/SharpCoreDB.Benchmarks/BatchUpdateDeferredIndexBenchmark.cs

@@ -90,6 +90,7 @@ public static void Main()
             Console.WriteLine("Performing 5,000 random UPDATEs with immediate index maintenance...\n");
 
             var random = new Random(42);
+            // NOSONAR:S2245 - fixed-seed Random for reproducible benchmark data (non-security).
             var stopwatch = Stopwatch.StartNew();
 
             for (int i = 0; i < 5000; i++)
@@ -123,6 +124,7 @@ public static void Main()
             Console.WriteLine("Performing 5,000 random UPDATEs with deferred index updates...\n");
 
             random = new Random(42);
+            // NOSONAR:S2245 - fixed-seed Random for reproducible benchmark data (non-security).
             stopwatch = Stopwatch.StartNew();
 
             try
@@ -188,6 +190,7 @@ public static void Main()
             try
             {
                 random = new Random(42);
+                // NOSONAR:S2245 - fixed-seed Random for reproducible benchmark data (non-security).
                 for (int i = 0; i < 10000; i++)
                 {
                     int id = random.Next(1, 10001);

tests/SharpCoreDB.Benchmarks/BatchUpdatePerformanceTest.cs

@@ -72,6 +72,7 @@ public static void Main()
             Console.WriteLine(new string('=', 70));
 
             var random = new Random(42);
+            // NOSONAR:S2245 - fixed-seed Random for reproducible benchmark data (non-security).
             var stopwatch = Stopwatch.StartNew();
 
             for (int i = 0; i < 5000; i++)
@@ -100,6 +101,7 @@ public static void Main()
             Console.WriteLine(new string('=', 70));
 
             random = new Random(42);
+            // NOSONAR:S2245 - fixed-seed Random for reproducible benchmark data (non-security).
             stopwatch = Stopwatch.StartNew();
 
             try

tests/SharpCoreDB.Benchmarks/BatchUpdateWalBenchmark.cs

@@ -88,6 +88,7 @@ public static void Main()
             Console.WriteLine("Performing 5,000 random UPDATEs WITHOUT batch WAL optimization...\n");
 
             var random = new Random(42);
+            // NOSONAR:S2245 - fixed-seed Random for reproducible benchmark data (non-security).
             var stopwatch = Stopwatch.StartNew();
 
             for (int i = 0; i < 5000; i++)
@@ -121,6 +122,7 @@ public static void Main()
             Console.WriteLine("Performing 5,000 random UPDATEs WITH batch WAL buffering...\n");
 
             random = new Random(42);
+            // NOSONAR:S2245 - fixed-seed Random for reproducible benchmark data (non-security).
             stopwatch = Stopwatch.StartNew();
 
             try
@@ -196,6 +198,7 @@ public static void Main()
                 }
 
                 random = new Random(42);
+                // NOSONAR:S2245 - fixed-seed Random for reproducible benchmark data (non-security).
                 stopwatch = Stopwatch.StartNew();
 
                 try

tests/SharpCoreDB.Benchmarks/DirectLookupBatchUpdateBenchmark.cs

@@ -94,6 +94,7 @@ public static void Main()
             Console.WriteLine("Performing 5,000 random updates using db.ExecuteSQL()...\n");
 
             var random = new Random(42);
+            // NOSONAR:S2245 - fixed-seed Random for reproducible benchmark data (non-security).
             var stopwatch = Stopwatch.StartNew();
 
             try

tests/SharpCoreDB.Benchmarks/InsertBatchOptimizationBenchmark.cs

@@ -112,6 +112,7 @@ private static List<Dictionary<string, object>> GenerateTestRows(int count)
     {
         var rows = new List<Dictionary<string, object>>(count);
         var random = new Random(42); // Seed for reproducibility
+        // NOSONAR:S2245 - fixed-seed Random for reproducible benchmark data (non-security).
 
         var firstNames = new[] { "John", "Jane", "Michael", "Sarah", "David", "Emma", "James", "Olivia", "Robert", "Sophia" };
         var lastNames = new[] { "Smith", "Johnson", "Williams", "Brown", "Jones", "Garcia", "Miller", "Davis", "Rodriguez", "Martinez" };

tests/SharpCoreDB.Benchmarks/PageBasedDirtyPageBenchmark.cs

@@ -80,6 +80,7 @@ public static void Main()
             // Baseline: Random updates without batch
             Console.WriteLine("Performing 5,000 random updates (baseline - no batch optimization)...\n");
             var random = new Random(42);
+            // NOSONAR:S2245 - fixed-seed Random for reproducible benchmark data (non-security).
             var baselineStopwatch = Stopwatch.StartNew();
 
             for (int i = 0; i < 5000; i++)
@@ -140,6 +141,7 @@ public static void Main()
             // Optimized: Batch updates with dirty page tracking
             Console.WriteLine("Performing 5,000 random updates (optimized - batch with dirty page tracking)...\n");
             random = new Random(42);
+            // NOSONAR:S2245 - fixed-seed Random for reproducible benchmark data (non-security).
             var optimizedStopwatch = Stopwatch.StartNew();
 
             db.BeginBatchUpdate();
@@ -209,6 +211,7 @@ public static void Main()
 
                 // Batch updates
                 random = new Random(42);
+                // NOSONAR:S2245 - fixed-seed Random for reproducible benchmark data (non-security).
                 var scaleStopwatch = Stopwatch.StartNew();
 
                 db.BeginBatchUpdate();

tests/SharpCoreDB.Benchmarks/ParallelBatchUpdateBenchmark.cs

@@ -72,6 +72,7 @@ public static void Main()
             Console.WriteLine("Performing 5,000 random multi-column updates (sequential)...\n");
 
             var random = new Random(42);
+            // NOSONAR:S2245 - fixed-seed Random for reproducible benchmark data (non-security).
             var stopwatch = Stopwatch.StartNew();
 
             try
@@ -130,6 +131,7 @@ public static void Main()
             Console.WriteLine("Performing 5,000 random multi-column updates (parallel)...\n");
 
             random = new Random(42);
+            // NOSONAR:S2245 - fixed-seed Random for reproducible benchmark data (non-security).
             stopwatch = Stopwatch.StartNew();
 
             try

tests/SharpCoreDB.Benchmarks/Phase2A_OptimizationBenchmark.cs

@@ -132,6 +132,7 @@ public int SelectStructRow_FastPath()
     private void PopulateTestDataOnce()
     {
         var random = new Random(42);
+        // NOSONAR:S2245 - fixed-seed Random for reproducible benchmark data (non-security).
 
         for (int i = 0; i < DATASET_SIZE; i++)
         {

tests/SharpCoreDB.Benchmarks/Phase2B_GroupByOptimizationBenchmark.cs

@@ -210,6 +210,7 @@ public int RepeatedGroupBy()
     private void PopulateTestData(int rowCount)
     {
         var random = new Random(42);
+        // NOSONAR:S2245 - fixed-seed Random for reproducible benchmark data (non-security).
 
         for (int i = 0; i < rowCount; i++)
         {
@@ -238,6 +239,7 @@ private double[] GenerateNumericArray(int size)
     {
         var array = new double[size];
         var random = new Random(42);
+        // NOSONAR:S2245 - fixed-seed Random for reproducible benchmark data (non-security).
 
         for (int i = 0; i < size; i++)
         {
@@ -328,6 +330,7 @@ private List<Dictionary<string, object>> GenerateTestRows(int count, int groupCo
     {
         var rows = new List<Dictionary<string, object>>(count);
         var random = new Random(42);
+        // NOSONAR:S2245 - fixed-seed Random for reproducible benchmark data (non-security).
 
         for (int i = 0; i < count; i++)
         {

tests/SharpCoreDB.Benchmarks/Phase2B_LockContentionBenchmark.cs

@@ -181,6 +181,7 @@ public int SelectWithLockTiming()
     private void PopulateTestData(int rowCount)
     {
         var random = new Random(42);
+        // NOSONAR:S2245 - fixed-seed Random for reproducible benchmark data (non-security).
 
         for (int i = 0; i < rowCount; i++)
         {
@@ -231,6 +232,7 @@ public void Setup()
         for (int i = 0; i < 50000; i++)
         {
             var random = new Random(42);
+            // NOSONAR:S2245 - fixed-seed Random for reproducible benchmark data (non-security).
             db.Database.ExecuteSQL($@"
                 INSERT INTO users (id, name, email, age, created_at, is_active)
                 VALUES ({i}, 'User{i}', 'user{i}@test.com', {18 + random.Next(65)},