feat: VS Code Extension for Policy Development

[zhaog100]

Closes #10

Summary

• VS Code extension with policy validation, IntelliSense, and developer commands
• JSON Schema for .aport.json / policy.json with real-time validation (version, name, rules, effect, action)
• 4 code snippets: policy pack, allow rule, deny rule, conditional rule
• 3 commands: Validate Current Policy, Create New Policy Pack, Insert Snippet
• Hover provider for action, effect, resource fields with inline documentation
• TypeScript with standard VS Code extension structure

Files Added

• examples/vscode-extension/ — extension manifest, schema, snippets, TS source, README

Wallet

TGu4W5T6q4KvLAbmXmZSRpUBNRCxr2aFTP (USDT TRC20)