Fix button styling in convert module to use proper colors

- Update viewLogBtn importance from Low to Medium for better visibility
- Update loadCfgBtn and saveCfgBtn importance from Low to Medium
- Update analyzeInterlaceBtn importance from Medium to High for prominence
- Update detectCropBtn importance from default to Medium
- Update cacheBrowseBtn importance from default to Medium
- Update resetSettingsBtn importance from Low to Medium

This ensures action buttons use appropriate colors instead of grey,
while dropdown blocks maintain their grey appearance through
NewColorCodedSelectContainer with colored borders.

Addresses UI issue where buttons were incorrectly styled as grey
when they should have proper button colors.

main.go

@@ -7214,6 +7214,7 @@ func buildConvertView(state *appState, src *videoSource) fyne.CanvasObject {
 			utils.SetTempDir(state.convert.TempDir)
 		}, state.window)
 	})
+	cacheBrowseBtn.Importance = widget.MediumImportance
 	cacheUseSystemBtn := widget.NewButton("Use System Temp", func() {
 		cacheDirEntry.SetText("")
 		state.convert.TempDir = ""
@@ -7226,7 +7227,7 @@ func buildConvertView(state *appState, src *videoSource) fyne.CanvasObject {
 			resetConvertDefaults()
 		}
 	})
-	resetSettingsBtn.Importance = widget.LowImportance
+	resetSettingsBtn.Importance = widget.MediumImportance
 
 	settingsContent := container.NewVBox(
 		settingsInfoContainer,