feat(upscale): add blur control

BUGS.md

@@ -93,12 +93,12 @@ None currently open.
 ## 🧭 Feature Requests (Planned)
 
 ### FEAT-003: Enhancement module blur control
-- **Status**: 🧭 PLANNED
+- **Status**: 🧭 IN PROGRESS
 - **Reporter**: Jake (2026-01-06)
 - **Module**: Enhancement
 - **Description**: Enhancement panel should include a blur control in addition to sharpen/denoise.
 - **Impact**: Medium - expected control in enhancement workflow
-- **Notes**: Add to enhancement UI alongside existing sliders.
+- **Notes**: Implemented blur controls in Upscale first; Enhancement UI still pending.
 
 ### FEAT-004: Upscale output quality should use Bitrate Mode controls
 - **Status**: 🧭 PLANNED

internal/state/manager.go

@@ -0,0 +1,34 @@
+package state
+
+import (
+	"fyne.io/fyne/v2/widget"
+	"sync"
+)
+
+type StateManager struct {
+	mu sync.RWMutex
+
+	// Current mode settings
+	crfMode         CRFMode
+	vbrMode         VBRMode
+	currentQuality  string
+	currentBitrate  string
+	currentCRFValue int64
+	currentVBRValue int64
+
+	// Registered widgets for synchronization
+	qualityWidgets []*widget.Select
+	bitrateWidgets []*widget.Select
+}
+
+type CRFMode string
+type VBRMode string
+
+const (
+	CRFManual      CRFMode = "manual"
+	CRFQuality     CRFMode = "quality"
+	CRFBitrate     CRFMode = "bitrate"
+	VBRStandard    VBRMode = "standard"
+	VBRHQ          VBRMode = "hq"
+	VBRConstrained VBRMode = "constrained"
+)

main.go

@@ -1096,6 +1096,8 @@ type appState struct {
 	upscaleFilterChain         []string // Transferred filters from Filters module
 	upscaleFrameRate           string   // Source, 24, 30, 60, or custom
 	upscaleMotionInterpolation bool     // Use motion interpolation for frame rate changes
+	upscaleBlurEnabled         bool     // Apply blur in upscale pipeline
+	upscaleBlurSigma           float64  // Blur strength (sigma)
 
 	// Snippet settings
 	snippetLength       int  // Length of snippet in seconds (default: 20)
@@ -5556,6 +5558,8 @@ func (s *appState) executeUpscaleJob(ctx context.Context, job *queue.Job, progre
 	useMotionInterp, _ := cfg["useMotionInterpolation"].(bool)
 	sourceFrameRate := toFloat(cfg["sourceFrameRate"])
 	qualityPreset, _ := cfg["qualityPreset"].(string)
+	blurEnabled, _ := cfg["blurEnabled"].(bool)
+	blurSigma := toFloat(cfg["blurSigma"])
 
 	if progressCallback != nil {
 		progressCallback(0)
@@ -5613,6 +5617,10 @@ func (s *appState) executeUpscaleJob(ctx context.Context, job *queue.Job, progre
 		}
 	}
 
+	if blurEnabled && blurSigma > 0 {
+		baseFilters = append(baseFilters, fmt.Sprintf("gblur=sigma=%.2f", blurSigma))
+	}
+
 	if useAI {
 		if aiBackend != "ncnn" {
 			return fmt.Errorf("AI upscaling backend not available")
@@ -14934,6 +14942,9 @@ func buildUpscaleView(state *appState) fyne.CanvasObject {
 		state.upscaleAIThreadsProc = 2
 		state.upscaleAIThreadsSave = 2
 	}
+	if state.upscaleBlurSigma <= 0 {
+		state.upscaleBlurSigma = 1.5
+	}
 
 	// Check AI availability on first load
 	if state.upscaleAIBackend == "" {
@@ -15069,6 +15080,36 @@ func buildUpscaleView(state *appState) fyne.CanvasObject {
 		widget.NewLabel("Lower CRF = higher quality/larger files"),
 	))
 
+	blurLabel := widget.NewLabel(fmt.Sprintf("Blur Strength: %.2f", state.upscaleBlurSigma))
+	blurSlider := widget.NewSlider(0.0, 8.0)
+	blurSlider.Step = 0.1
+	blurSlider.Value = state.upscaleBlurSigma
+	blurSlider.OnChanged = func(v float64) {
+		state.upscaleBlurSigma = v
+		blurLabel.SetText(fmt.Sprintf("Blur Strength: %.2f", v))
+	}
+
+	blurCheck := widget.NewCheck("Enable Blur", func(checked bool) {
+		state.upscaleBlurEnabled = checked
+		if checked {
+			blurSlider.Enable()
+		} else {
+			blurSlider.Disable()
+		}
+	})
+	blurCheck.SetChecked(state.upscaleBlurEnabled)
+	if state.upscaleBlurEnabled {
+		blurSlider.Enable()
+	} else {
+		blurSlider.Disable()
+	}
+
+	blurSection := widget.NewCard("Blur (Optional)", "", container.NewVBox(
+		widget.NewLabel("Apply a soft blur during upscale processing"),
+		blurCheck,
+		container.NewVBox(blurLabel, blurSlider),
+	))
+
 	// Frame Rate Section
 	frameRateLabel := widget.NewLabel(fmt.Sprintf("Frame Rate: %s", state.upscaleFrameRate))
 	frameRateSelect := widget.NewSelect([]string{"Source", "23.976", "24", "25", "29.97", "30", "50", "59.94", "60"}, func(s string) {
@@ -15437,6 +15478,8 @@ func buildUpscaleView(state *appState) fyne.CanvasObject {
 				"aiOutputFormat":         state.upscaleAIOutputFormat,
 				"applyFilters":           state.upscaleApplyFilters,
 				"filterChain":            state.upscaleFilterChain,
+				"blurEnabled":            state.upscaleBlurEnabled,
+				"blurSigma":              state.upscaleBlurSigma,
 				"duration":               state.upscaleFile.Duration,
 				"sourceFrameRate":        state.upscaleFile.FrameRate,
 				"frameRate":              state.upscaleFrameRate,
@@ -15490,6 +15533,7 @@ func buildUpscaleView(state *appState) fyne.CanvasObject {
 		traditionalSection,
 		resolutionSection,
 		qualitySection,
+		blurSection,
 		frameRateSection,
 		aiSection,
 		filterIntegrationSection,