Enhance design-system-inspector-plugin with Advanced CSS Debugger

[tyevco]

Current: Design token analysis
Add: CSS-in-JS runtime inspector, cascade specificity analyzer, unused CSS detector, layout thrashing detector

[tycoff]

Current Capabilities: Design token analysis, color/typography/spacing inspection
Enhancement Scope: Complete CSS debugging and analysis suite

Add These Features:

• CSS-in-JS runtime inspector (styled-components, emotion)
• Cascade specificity analyzer with conflict resolution
• Unused CSS detector with tree-shaking suggestions
• Style recomputation profiler
• Layout thrashing detector
• CSS containment analyzer
• Grid/Flexbox layout visualizer with debugging
• CSS animations performance impact analyzer

Implementation: Add advanced CSS analysis tabs
Priority: Medium - Completes design system story