Add image processing benchmarks and UI folder open buttons

- Added MaddoShared.Benchmarks project with BenchmarkDotNet for comprehensive image processing performance tests (parallel, chunk, size, stress).
- Included helper for generating test images and custom configs to ensure InProcess toolchain for .NET Windows compatibility.
- Added cross-platform scripts to run benchmarks easily.
- Updated .gitignore for benchmark artifacts and temp files.
- Exposed GetFilesToProcessPublic in ImageCreationStuff for testability.
- Added file name sanitization in ImageCreatorSharp to prevent IO errors.
- Enhanced WinForms UI: added "Open" buttons for source/destination folders, handled folder opening in Explorer, and improved user messaging and layout.
- Updated solution file to include new benchmark project.

run-benchmarks.sh

@@ -0,0 +1,134 @@
+#!/bin/bash
+
+# Image Processing Benchmark Runner (Linux/Mac)
+# This script provides easy access to common benchmark scenarios
+
+show_help() {
+    cat << EOF
+Image Processing Benchmark Runner
+==================================
+
+Usage: ./run-benchmarks.sh [scenario] [--fast] [--verbose]
+
+Scenarios:
+  all       - Run all benchmarks (60-120 minutes)
+  quick     - Fast test run for development (5-10 minutes)
+  parallel  - Test parallel processing strategies (20-30 minutes)
+  chunks    - Optimize chunk size (20-30 minutes)
+  sizes     - Test different image sizes (45-90 minutes)
+  stress    - Large-scale stress test (2-4 hours)
+  help      - Show this help message
+
+Flags:
+  --fast    - Use dry run for faster but less accurate results
+  --verbose - Show detailed output
+
+Examples:
+  ./run-benchmarks.sh quick
+  ./run-benchmarks.sh parallel --fast
+  ./run-benchmarks.sh stress --verbose
+
+Results will be saved to: MaddoShared.Benchmarks/BenchmarkDotNet.Artifacts/results/
+EOF
+}
+
+run_benchmark() {
+    local filter=$1
+    local description=$2
+    
+    echo ""
+    echo "========================================"
+    echo " $description"
+    echo "========================================"
+    echo ""
+    
+    local args="-c Release"
+    
+    if [ -n "$filter" ]; then
+        args="$args -- --filter \"$filter\""
+    fi
+    
+    if [ "$fast_mode" = true ]; then
+        args="$args --job dry"
+    fi
+    
+    if [ "$verbose_mode" = true ]; then
+        args="$args --verbose"
+    fi
+    
+    cd MaddoShared.Benchmarks
+    eval "dotnet run $args"
+    cd ..
+}
+
+# Parse arguments
+scenario="${1:-help}"
+fast_mode=false
+verbose_mode=false
+
+shift
+while [ $# -gt 0 ]; do
+    case "$1" in
+        --fast)
+            fast_mode=true
+            ;;
+        --verbose)
+            verbose_mode=true
+            ;;
+    esac
+    shift
+done
+
+# Main execution
+case "$scenario" in
+    help)
+        show_help
+        ;;
+    
+    all)
+        echo "Running ALL benchmarks..."
+        echo "This will take 60-120 minutes. Press Ctrl+C to cancel."
+        echo ""
+        sleep 3
+        run_benchmark "" "All Benchmarks"
+        ;;
+    
+    quick)
+        echo "Running QUICK test..."
+        run_benchmark "*ImageProcessingBenchmarks*" "Quick Development Test"
+        ;;
+    
+    parallel)
+        echo "Running PARALLEL processing benchmarks..."
+        run_benchmark "*ImageProcessingBenchmarks*" "Parallel Processing Strategies"
+        ;;
+    
+    chunks)
+        echo "Running CHUNK SIZE optimization..."
+        run_benchmark "*ChunkSizeBenchmarks*" "Chunk Size Optimization"
+        ;;
+    
+    sizes)
+        echo "Running IMAGE SIZE comparison..."
+        run_benchmark "*ImageSizeBenchmarks*" "Image Size Impact Analysis"
+        ;;
+    
+    stress)
+        echo "Running STRESS TEST..."
+        echo "WARNING: This will take 2-4 hours and use significant disk space!"
+        echo "Press Ctrl+C within 5 seconds to cancel..."
+        echo ""
+        sleep 5
+        run_benchmark "*StressTestBenchmark*" "Large-Scale Stress Test"
+        ;;
+    
+    *)
+        echo "Unknown scenario: $scenario"
+        echo "Run './run-benchmarks.sh help' for usage information"
+        exit 1
+        ;;
+esac
+
+echo ""
+echo "Benchmark execution complete!"
+echo "Results saved to: MaddoShared.Benchmarks/BenchmarkDotNet.Artifacts/results/"