Enhance VS Code extension settings panel and fix packaging

- Fix .vscodeignore to include all node_modules (fixes form-data missing error)
- Add full lrm.json configuration support to settings panel
- Register all VS Code settings in package.json (scanCSharp, scanRazor, scanXaml, resourceClasses, localizationMethods, enablePlaceholderValidation)
- Add AI provider settings with collapsible sections (Ollama, OpenAI, Claude, Azure OpenAI, Azure Translator, Lingva, MyMemory)
- Change model selectors to allow custom input via datalist
- Update VSCODE_EXTENSION_PLAN.md with current feature status

Author: nickprotop