Add Canonical JSON serialization library with tests and documentation

- Implemented CanonJson class for deterministic JSON serialization and hashing.
- Added unit tests for CanonJson functionality, covering various scenarios including key sorting, handling of nested objects, arrays, and special characters.
- Created project files for the Canonical JSON library and its tests, including necessary package references.
- Added README.md for library usage and API reference.
- Introduced RabbitMqIntegrationFactAttribute for conditional RabbitMQ integration tests.

bench/smart-diff/run-benchmark.sh

@@ -0,0 +1,135 @@
+#!/usr/bin/env bash
+# run-benchmark.sh
+# Smart-Diff Benchmark Runner
+# Sprint: SPRINT_3850_0001_0001
+
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+BENCH_ROOT="$SCRIPT_DIR"
+RESULTS_DIR="$BENCH_ROOT/results/$(date -u +%Y%m%d_%H%M%S)"
+
+# Parse arguments
+BASELINE_MODE="naive"
+COMPARE_MODE="smart"
+VERBOSE=false
+
+while [[ $# -gt 0 ]]; do
+    case $1 in
+        --baseline)
+            BASELINE_MODE="$2"
+            shift 2
+            ;;
+        --compare)
+            COMPARE_MODE="$2"
+            shift 2
+            ;;
+        --verbose|-v)
+            VERBOSE=true
+            shift
+            ;;
+        *)
+            echo "Unknown option: $1"
+            exit 1
+            ;;
+    esac
+done
+
+echo "╔════════════════════════════════════════════════╗"
+echo "║         Smart-Diff Benchmark Suite             ║"
+echo "╚════════════════════════════════════════════════╝"
+echo ""
+echo "Configuration:"
+echo "  Baseline mode: $BASELINE_MODE"
+echo "  Compare mode:  $COMPARE_MODE"
+echo "  Results dir:   $RESULTS_DIR"
+echo ""
+
+mkdir -p "$RESULTS_DIR"
+
+# Function to run a test case
+run_test_case() {
+    local test_id="$1"
+    local description="$2"
+    local base_sbom="$3"
+    local target_sbom="$4"
+    local expected_file="$5"
+
+    echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
+    echo "Test: $test_id - $description"
+    echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
+
+    local start_time=$(date +%s%3N)
+    
+    # Run smart-diff
+    if command -v dotnet &> /dev/null; then
+        dotnet run --project "$SCRIPT_DIR/../../src/Scanner/__Libraries/StellaOps.Scanner.SmartDiff" -- \
+            --base "$base_sbom" \
+            --target "$target_sbom" \
+            --output "$RESULTS_DIR/$test_id.diff.json" \
+            --format json 2>/dev/null || true
+    fi
+
+    local end_time=$(date +%s%3N)
+    local elapsed=$((end_time - start_time))
+
+    echo "  Time: ${elapsed}ms"
+    
+    # Verify determinism by running twice
+    if [ -f "$RESULTS_DIR/$test_id.diff.json" ]; then
+        local hash1=$(sha256sum "$RESULTS_DIR/$test_id.diff.json" | cut -d' ' -f1)
+        
+        if command -v dotnet &> /dev/null; then
+            dotnet run --project "$SCRIPT_DIR/../../src/Scanner/__Libraries/StellaOps.Scanner.SmartDiff" -- \
+                --base "$base_sbom" \
+                --target "$target_sbom" \
+                --output "$RESULTS_DIR/$test_id.diff.run2.json" \
+                --format json 2>/dev/null || true
+        fi
+
+        if [ -f "$RESULTS_DIR/$test_id.diff.run2.json" ]; then
+            local hash2=$(sha256sum "$RESULTS_DIR/$test_id.diff.run2.json" | cut -d' ' -f1)
+            
+            if [ "$hash1" = "$hash2" ]; then
+                echo "  ✓ Determinism verified"
+            else
+                echo "  ✗ Determinism FAILED (different hashes)"
+            fi
+        fi
+    else
+        echo "  ⊘ Skipped (dotnet not available or project missing)"
+    fi
+
+    echo ""
+}
+
+# Test Case 1: Layer-Aware Diff (using fixtures)
+if [ -f "$BENCH_ROOT/fixtures/base-alpine-3.18.sbom.cdx.json" ]; then
+    run_test_case "TC-001-layer-added" \
+        "Layer addition detection" \
+        "$BENCH_ROOT/fixtures/base-alpine-3.18.sbom.cdx.json" \
+        "$BENCH_ROOT/fixtures/base-alpine-3.19.sbom.cdx.json" \
+        "$BENCH_ROOT/fixtures/expected/tc001-layer-added.diff.json"
+else
+    echo "ℹ️  Skipping TC-001: Fixtures not found"
+    echo "   Run './tools/generate-fixtures.sh' to create test fixtures"
+fi
+
+# Generate summary
+echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
+echo "Summary"
+echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
+echo "Results saved to: $RESULTS_DIR"
+
+# Create summary JSON
+cat > "$RESULTS_DIR/summary.json" <<EOF
+{
+  "benchmark": "smart-diff",
+  "timestamp": "$(date -u +%Y-%m-%dT%H:%M:%SZ)",
+  "baseline_mode": "$BASELINE_MODE",
+  "compare_mode": "$COMPARE_MODE",
+  "results_dir": "$RESULTS_DIR"
+}
+EOF
+
+echo "Done."