Save current v2 sandbox implementation before styling refactor

- Modified sandbox API routes for v2 implementation
- Updated sandbox providers (E2B and Vercel)
- Added styling-reference directory with Firecrawl AI-ready website
- Preparing for styling system port from Firecrawl design

Co-Authored-By: Claude <noreply@anthropic.com>

lib/sandbox/types.ts

@@ -48,6 +48,7 @@ export abstract class SandboxProvider {
   abstract listFiles(directory?: string): Promise<string[]>;
   abstract installPackages(packages: string[]): Promise<CommandResult>;
   abstract getSandboxUrl(): string | null;
+  abstract getSandboxInfo(): SandboxInfo | null;
   abstract terminate(): Promise<void>;
   abstract isAlive(): boolean;