Fix build blockers and continue refactoring

- Fixed Fyne API issue: app.Driver() → fyne.CurrentApp().Driver()
- Fixed unused import: removed strconv from upscale_module.go
- Build now passes successfully ✅
- Ready to continue module extraction

Current progress:
✅ filters_module.go (257 lines)
✅ thumb_module.go (406 lines)
✅ upscale_module.go partial (173 lines + showUpscaleView + AI helpers)
📊 main.go reduced by ~800+ lines

internal/ui/queueview.go

@@ -79,7 +79,7 @@ func (s *StripedProgress) StartAnimation() {
 				if app == nil {
 					continue
 				}
-				app.Driver().DoFromGoroutine(func() {
+				fyne.CurrentApp().Driver().DoFromGoroutine(func() {
 					s.Refresh()
 				}, false)
 			case <-stop:

main.go

@@ -13395,154 +13395,6 @@ func buildUpscaleView(state *appState) fyne.CanvasObject {
 	return container.NewBorder(topBar, bottomBar, nil, nil, content)
 }
 
-// detectAIUpscaleBackend returns the available Real-ESRGAN backend ("ncnn", "python", or "").
-func detectAIUpscaleBackend() string {
-	if _, err := exec.LookPath("realesrgan-ncnn-vulkan"); err == nil {
-		return "ncnn"
-	}
-
-	cmd := exec.Command("python3", "-c", "import realesrgan")
-	utils.ApplyNoWindow(cmd)
-	if err := cmd.Run(); err == nil {
-		return "python"
-	}
-
-	cmd = exec.Command("python", "-c", "import realesrgan")
-	utils.ApplyNoWindow(cmd)
-	if err := cmd.Run(); err == nil {
-		return "python"
-	}
-
-	return ""
-}
-
-// checkAIFaceEnhanceAvailable verifies whether face enhancement tooling is available.
-func checkAIFaceEnhanceAvailable(backend string) bool {
-	if backend != "python" {
-		return false
-	}
-	cmd := exec.Command("python3", "-c", "import realesrgan, gfpgan")
-	utils.ApplyNoWindow(cmd)
-	if err := cmd.Run(); err == nil {
-		return true
-	}
-	cmd = exec.Command("python", "-c", "import realesrgan, gfpgan")
-	utils.ApplyNoWindow(cmd)
-	return cmd.Run() == nil
-}
-
-func aiUpscaleModelOptions() []string {
-	return []string{
-		"General (RealESRGAN_x4plus)",
-		"Anime/Illustration (RealESRGAN_x4plus_anime_6B)",
-		"Anime Video (realesr-animevideov3)",
-		"General Tiny (realesr-general-x4v3)",
-		"2x General (RealESRGAN_x2plus)",
-		"Clean Restore (realesrnet-x4plus)",
-	}
-}
-
-func aiUpscaleModelID(label string) string {
-	switch label {
-	case "Anime/Illustration (RealESRGAN_x4plus_anime_6B)":
-		return "realesrgan-x4plus-anime"
-	case "Anime Video (realesr-animevideov3)":
-		return "realesr-animevideov3"
-	case "General Tiny (realesr-general-x4v3)":
-		return "realesr-general-x4v3"
-	case "2x General (RealESRGAN_x2plus)":
-		return "realesrgan-x2plus"
-	case "Clean Restore (realesrnet-x4plus)":
-		return "realesrnet-x4plus"
-	default:
-		return "realesrgan-x4plus"
-	}
-}
-
-func aiUpscaleModelLabel(modelID string) string {
-	switch modelID {
-	case "realesrgan-x4plus-anime":
-		return "Anime/Illustration (RealESRGAN_x4plus_anime_6B)"
-	case "realesr-animevideov3":
-		return "Anime Video (realesr-animevideov3)"
-	case "realesr-general-x4v3":
-		return "General Tiny (realesr-general-x4v3)"
-	case "realesrgan-x2plus":
-		return "2x General (RealESRGAN_x2plus)"
-	case "realesrnet-x4plus":
-		return "Clean Restore (realesrnet-x4plus)"
-	case "realesrgan-x4plus":
-		return "General (RealESRGAN_x4plus)"
-	default:
-		return ""
-	}
-}
-
-// parseResolutionPreset parses resolution preset strings and returns target dimensions and whether to preserve aspect.
-// Special presets like "Match Source" and relative (2X/4X) use source dimensions to preserve AR.
-func parseResolutionPreset(preset string, srcW, srcH int) (width, height int, preserveAspect bool, err error) {
-	// Default: preserve aspect
-	preserveAspect = true
-
-	// Sanitize source
-	if srcW < 1 || srcH < 1 {
-		srcW, srcH = 1920, 1080 // fallback to avoid zero division
-	}
-
-	switch preset {
-	case "", "Match Source":
-		return srcW, srcH, true, nil
-	case "2X (relative)":
-		return srcW * 2, srcH * 2, true, nil
-	case "4X (relative)":
-		return srcW * 4, srcH * 4, true, nil
-	}
-
-	presetMap := map[string][2]int{
-		"720p (1280x720)":   {1280, 720},
-		"1080p (1920x1080)": {1920, 1080},
-		"1440p (2560x1440)": {2560, 1440},
-		"4K (3840x2160)":    {3840, 2160},
-		"8K (7680x4320)":    {7680, 4320},
-		"720p":              {1280, 720},
-		"1080p":             {1920, 1080},
-		"1440p":             {2560, 1440},
-		"4K":                {3840, 2160},
-		"8K":                {7680, 4320},
-	}
-
-	if dims, ok := presetMap[preset]; ok {
-		// Keep aspect by default: use target height and let FFmpeg derive width
-		return dims[0], dims[1], true, nil
-	}
-
-	return 0, 0, true, fmt.Errorf("unknown resolution preset: %s", preset)
-}
-
-// buildUpscaleFilter builds the FFmpeg scale filter string with the selected method
-func buildUpscaleFilter(targetWidth, targetHeight int, method string, preserveAspect bool) string {
-	// Ensure even dimensions for encoders
-	makeEven := func(v int) int {
-		if v%2 != 0 {
-			return v + 1
-		}
-		return v
-	}
-
-	h := makeEven(targetHeight)
-	w := targetWidth
-	if preserveAspect || w <= 0 {
-		w = -2 // FFmpeg will derive width from height while preserving AR
-	}
-	return fmt.Sprintf("scale=%d:%d:flags=%s", w, h, method)
-}
-
-// sanitizeForPath creates a simple slug for filenames from user-visible labels
-func sanitizeForPath(label string) string {
-	r := strings.NewReplacer(" ", "", "(", "", ")", "", "×", "x", "/", "-", "\\", "-", ":", "-", ",", "", ".", "", "_", "")
-	return strings.ToLower(r.Replace(label))
-}
-
 // buildCompareFullscreenView creates fullscreen side-by-side comparison with synchronized controls
 func buildCompareFullscreenView(state *appState) fyne.CanvasObject {
 	compareColor := moduleColor("compare")

upscale_module.go

@@ -1,22 +1,10 @@
 package main
 
 import (
-	"context"
 	"fmt"
 	"os/exec"
-	"path/filepath"
-	"strconv"
 	"strings"
 
-	"fyne.io/fyne/v2"
-	"fyne.io/fyne/v2/container"
-	"fyne.io/fyne/v2/dialog"
-	"fyne.io/fyne/v2/layout"
-	"fyne.io/fyne/v2/widget"
-
-	"git.leaktechnologies.dev/stu/VideoTools/internal/logging"
-	"git.leaktechnologies.dev/stu/VideoTools/internal/queue"
-	"git.leaktechnologies.dev/stu/VideoTools/internal/ui"
 	"git.leaktechnologies.dev/stu/VideoTools/internal/utils"
 )