VS Code extension for real-time hosting module analysis

[mladenovic-13]

Implement HostingLint VS Code extension (Milestone 3) with real-time analysis powered by @hostinglint/core's analyzeAuto() API. Supports PHP/WHMCS, Perl/cPanel, and Dockerfile/OpenPanel files with inline warnings, hover info, and quick fixes.

Summary

• Add unified analyzeAuto() entry point in core with platform auto-detection and rule
  overrides
• Refactor CLI to use analyzeAuto() from core, removing ~60 lines of duplicated logic
• Fix security/bestPractices defaulting to undefined instead of true in
  analyzeAuto()
• VS Code extension modules: diagnostics, config cache, code actions, hover, logger
• Config file support (.hostinglintrc.json) with FileSystemWatcher for auto-reload
• Quick fixes: auto-fix from fixAction + disable-line for PHP (//) and Perl (#)
• Hover: rule ID, message, category, platform, severity, suggested fix
• esbuild bundle (~72KB), debounced onType analysis (300ms)
• 22 new tests (13 core + 9 vscode), 179 total passing
• Extension README and updated ARCHITECTURE.md

Type of Change

• Bug fix
• New feature
• New rule
• Documentation update
• Refactoring
• Other: ___

Checklist

• npm run validate passes (lint + typecheck + tests + build)
• New rules have positive and negative test cases
• Documentation updated if needed
• No any types introduced