fix: cream background on every style, warm highlight on cursor row

Every Lip Gloss style now has Background(ScreenBg) so ANSI sequences
carry the cream color inherently. Previously only PadLine added bg
to padding spaces, but inner escape codes reset the background.

All spacing between styled segments uses bg()/wbg() helpers.
Cursor row elements use Background(Warm) for highlight.

cli/internal/theme/theme.go

@@ -57,6 +57,11 @@ func CategoryColor(cat string) color.Color {
 }
 
 // ─── Reusable styles ─────────────────────────────────────────
+//
+// IMPORTANT: Every style MUST have Background(ScreenBg) so the cream
+// background propagates through all ANSI sequences. Wrapping
+// already-styled text with a background style does NOT work because
+// inner escape sequences reset the background.
 
 var (
 	// Title bar
@@ -69,44 +74,53 @@ var (
 	// Header / breadcrumb
 	Breadcrumb = lipgloss.NewStyle().
 			Foreground(Mid).
+			Background(ScreenBg).
 			Bold(false)
 
 	BreadcrumbActive = lipgloss.NewStyle().
 				Foreground(Dark).
+				Background(ScreenBg).
 				Bold(true)
 
 	// File row
 	FileName = lipgloss.NewStyle().
 			Foreground(Dark).
+			Background(ScreenBg).
 			Bold(true)
 
 	FileSize = lipgloss.NewStyle().
-			Foreground(Light)
+			Foreground(Light).
+			Background(ScreenBg)
 
 	ExtBadge = func(c color.Color) lipgloss.Style {
 		return lipgloss.NewStyle().
 			Foreground(c).
+			Background(ScreenBg).
 			Bold(true)
 	}
 
 	// Status indicators
 	StatusIdle = lipgloss.NewStyle().
 			Foreground(Light).
+			Background(ScreenBg).
 			Italic(true)
 
 	StatusConverting = lipgloss.NewStyle().
 				Foreground(Pink).
+				Background(ScreenBg).
 				Bold(true)
 
 	StatusDone = lipgloss.NewStyle().
 			Foreground(Mint).
+			Background(ScreenBg).
 			Bold(true)
 
 	StatusError = lipgloss.NewStyle().
 			Foreground(Red).
+			Background(ScreenBg).
 			Bold(true)
 
-	// Buttons / actions
+	// Buttons / actions (these keep their own bg colors)
 	ButtonPrimary = lipgloss.NewStyle().
 			Foreground(lipgloss.Color("#ffffff")).
 			Background(Pink).
@@ -121,50 +135,67 @@ var (
 
 	// Progress bar
 	ProgressFilled = lipgloss.NewStyle().
-			Foreground(Pink)
+			Foreground(Pink).
+			Background(ScreenBg)
 
 	ProgressEmpty = lipgloss.NewStyle().
-			Foreground(BorderCl)
+			Foreground(BorderCl).
+			Background(ScreenBg)
 
 	// Help / footer
 	Help = lipgloss.NewStyle().
 		Foreground(Light).
+		Background(ScreenBg).
 		Italic(true)
 
 	// Cursor / selection
 	Selected = lipgloss.NewStyle().
 			Bold(true).
-			Foreground(Pink)
+			Foreground(Pink).
+			Background(ScreenBg)
 
 	Unselected = lipgloss.NewStyle().
-			Foreground(Dark)
+			Foreground(Dark).
+			Background(ScreenBg)
 
 	// Divider
 	Divider = lipgloss.NewStyle().
-		Foreground(BorderCl)
+		Foreground(BorderCl).
+		Background(ScreenBg)
 
 	// Logo / branding
 	Logo = lipgloss.NewStyle().
 		Foreground(Pink).
+		Background(ScreenBg).
 		Bold(true)
 )
 
-// PadLine pads a single rendered line to the full terminal width and applies
-// the cream background behind ALL content (not just the padding). This is
-// achieved by placing the line inside a full-width style with Background set.
+// BgStyle returns a plain style with just the cream background, useful
+// for spacing characters that need to carry the background color.
+var BgStyle = lipgloss.NewStyle().Background(ScreenBg)
+
+// WarmBgStyle returns a plain style with the warm highlight background.
+var WarmBgStyle = lipgloss.NewStyle().Background(Warm)
+
+// PadLine pads a single rendered line to the full terminal width with
+// cream background spaces on the right edge.
 func PadLine(line string, width int) string {
-	return PadLineWithBg(line, width, ScreenBg)
+	w := lipgloss.Width(line)
+	if w >= width {
+		return line
+	}
+	pad := BgStyle.Render(strings.Repeat(" ", width-w))
+	return line + pad
 }
 
 // PadLineWithBg pads a line to full width with a specific background color.
 func PadLineWithBg(line string, width int, bg color.Color) string {
 	w := lipgloss.Width(line)
 	if w >= width {
-		// Even if the line is already wide enough, wrap with background
-		return lipgloss.NewStyle().Background(bg).Render(line)
+		return line
 	}
-	pad := strings.Repeat(" ", width-w)
-	return lipgloss.NewStyle().Background(bg).Render(line + pad)
+	pad := lipgloss.NewStyle().Background(bg).Render(strings.Repeat(" ", width-w))
+	return line + pad
 }
 
 // FillBlankLines returns n blank lines fully painted with the screen
@@ -173,9 +204,7 @@ func FillBlankLines(n, width int) string {
 	if n <= 0 {
 		return ""
 	}
-	blankLine := lipgloss.NewStyle().
-		Background(ScreenBg).
-		Render(strings.Repeat(" ", width))
+	blankLine := BgStyle.Render(strings.Repeat(" ", width))
 	lines := make([]string, n)
 	for i := range lines {
 		lines[i] = blankLine