feat: add multiple package sync sources and API integration

- Added undici dependency and implemented three package fetcher variants (simple text parsing, v2 with better error handling, and official repository sync)
- Integrated real API calls in PlatformSelector and PackageBrowser components with fallback to mock data
- Extended sync API route to support multiple data sources (debian-simple, ubuntu-simple, debian-official-v2, etc.) with platform initialization

src/app/api/init-platforms/route.ts

@@ -0,0 +1,18 @@
+import { NextResponse } from 'next/server'
+import { PlatformInitializer } from '@/services/platformInitializer'
+
+export async function POST() {
+  try {
+    await PlatformInitializer.initializePlatforms()
+    return NextResponse.json({ 
+      success: true, 
+      message: 'Platforms initialized successfully' 
+    })
+  } catch (error) {
+    console.error('Error initializing platforms:', error)
+    return NextResponse.json(
+      { error: 'Failed to initialize platforms' },
+      { status: 500 }
+    )
+  }
+}