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.ps1

@@ -0,0 +1,124 @@
+# Image Processing Benchmark Runner
+# This script provides easy access to common benchmark scenarios
+
+param(
+    [Parameter(Position=0)]
+    [ValidateSet("all", "quick", "parallel", "chunks", "sizes", "stress", "help")]
+    [string]$Scenario = "help",
+    
+    [switch]$Fast,
+    [switch]$DetailedOutput
+)
+
+$projectPath = "MaddoShared.Benchmarks"
+
+function Show-Help {
+    Write-Host @"
+Image Processing Benchmark Runner
+==================================
+
+Usage: .\run-benchmarks.ps1 [scenario] [-Fast] [-DetailedOutput]
+
+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
+  -DetailedOutput - Show detailed output
+
+Examples:
+  .\run-benchmarks.ps1 quick
+  .\run-benchmarks.ps1 parallel -Fast
+  .\run-benchmarks.ps1 stress -DetailedOutput
+
+Results will be saved to: MaddoShared.Benchmarks\BenchmarkDotNet.Artifacts\results\
+"@
+}
+
+function Run-Benchmark {
+    param(
+        [string]$Filter,
+        [string]$Description
+    )
+    
+    Write-Host "`n========================================" -ForegroundColor Cyan
+    Write-Host " $Description" -ForegroundColor Cyan
+    Write-Host "========================================`n" -ForegroundColor Cyan
+    
+    $args = @("-c", "Release")
+    
+    if ($Filter) {
+        $args += @("--", "--filter", $Filter)
+    }
+    
+    # Note: We don't pass --job arguments anymore because they override
+    # the InProcess toolchain configuration needed for Windows compatibility
+    if ($Fast) {
+        Write-Host "Note: Fast mode (-Fast) requested but not using --job dry" -ForegroundColor Yellow
+        Write-Host "Reason: --job arguments override InProcess toolchain config" -ForegroundColor Yellow
+        Write-Host "The benchmark will run with the default InProcessConfig settings.`n" -ForegroundColor Yellow
+    }
+    
+    if ($DetailedOutput) {
+        $args += "--verbosity", "detailed"
+    }
+    
+    Push-Location $projectPath
+    try {
+        dotnet run @args
+    }
+    finally {
+        Pop-Location
+    }
+}
+
+# Main execution
+switch ($Scenario) {
+    "help" {
+        Show-Help
+    }
+    
+    "all" {
+        Write-Host "Running ALL benchmarks..." -ForegroundColor Yellow
+        Write-Host "This will take 60-120 minutes. Press Ctrl+C to cancel.`n" -ForegroundColor Yellow
+        Start-Sleep -Seconds 3
+        Run-Benchmark "" "All Benchmarks"
+    }
+    
+    "quick" {
+        Write-Host "Running QUICK test..." -ForegroundColor Green
+        Run-Benchmark "*ImageProcessingBenchmarks*" "Quick Development Test"
+    }
+    
+    "parallel" {
+        Write-Host "Running PARALLEL processing benchmarks..." -ForegroundColor Green
+        Run-Benchmark "*ImageProcessingBenchmarks*" "Parallel Processing Strategies"
+    }
+    
+    "chunks" {
+        Write-Host "Running CHUNK SIZE optimization..." -ForegroundColor Green
+        Run-Benchmark "*ChunkSizeBenchmarks*" "Chunk Size Optimization"
+    }
+    
+    "sizes" {
+        Write-Host "Running IMAGE SIZE comparison..." -ForegroundColor Green
+        Run-Benchmark "*ImageSizeBenchmarks*" "Image Size Impact Analysis"
+    }
+    
+    "stress" {
+        Write-Host "Running STRESS TEST..." -ForegroundColor Red
+        Write-Host "WARNING: This will take 2-4 hours and use significant disk space!" -ForegroundColor Red
+        Write-Host "Press Ctrl+C within 5 seconds to cancel...`n" -ForegroundColor Red
+        Start-Sleep -Seconds 5
+        Run-Benchmark "*StressTestBenchmark*" "Large-Scale Stress Test"
+    }
+}
+
+Write-Host "`nBenchmark execution complete!" -ForegroundColor Green
+Write-Host "Results saved to: $projectPath\BenchmarkDotNet.Artifacts\results\" -ForegroundColor Green