feat(control-panel): Improve category header styling

[VolkovsaVSA]

Summary

This PR enhances the visual appearance of category headers in the Control Panel module to improve visual hierarchy and readability.

Changes

• Semi-transparent background: Added a subtle white background (alpha = 0.08) with rounded corners (8dp) to category headers
• Bold typography: Increased font size to 18sp with FontWeight.Bold for better visual distinction
• Improved spacing: Added horizontal padding (12dp) and spacing between category sections (8dp)

Visual Comparison

Before	After
Category headers appear as plain text, blending with items below	Category headers have subtle background, larger bold text, better separation

Technical Details

// Category header styling
Row(
    modifier = Modifier
       .fillMaxWidth()
       .background(
           color = Color.White.copy(alpha = 0.08f),
           shape = RoundedCornerShape(8.dp)
       )
       .padding(horizontal = 12.dp, vertical = 12.dp),
) {
    Text(
        text = category,
        fontSize = 18.sp,
        fontWeight = FontWeight.Bold,
    )
}

Screenshots