Replace sample dashboard data with rolldown version statistics

[Copilot]

This PR transforms the Vibe Dashboard to display meaningful rolldown bundler performance data instead of placeholder sample data. The dashboard now visualizes real build statistics from different rolldown-vite versions.

Changes Made

Data Integration:

• Imports rolldown-version-stats.json containing build statistics for rolldown versions 7.1.0 through 7.1.4
• Transforms raw JSON data into chart-compatible formats for visualization

New Dashboard Metrics:

1. Build Time Performance - Shows build time (ms) across different rolldown versions
2. Bundle Size Comparison - Displays total bundle size (KB) for each version
3. File Type Breakdown - Stacked bar chart showing size distribution by file type (JS, CSS, HTML, Other)

Updated Statistics Cards:

• Average Build Time: 1563ms across 5 versions
• Latest Bundle Size: 555KB (v7.1.4)
• Total File Types: 4 categories tracked
• Versions Tested: Range from 7.1.0 to 7.1.4

Technical Implementation

The implementation leverages the existing Recharts infrastructure while replacing the sample data arrays (salesData, userActivityData, revenueData) with real rolldown statistics. The file type breakdown uses a stacked bar chart with appropriate colors for each file type (JavaScript in yellow, CSS in blue, HTML in red, Other in gray).

All interactive features remain functional:

• Navigation buttons to switch between chart views
• Hover tooltips showing detailed values
• Responsive design across different screen sizes
• Legend and axis labels for clarity

Fixes #21.

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