Uploading custom instructions markdown files

[krithika7402]

Description

• Added a file upload method for custom instructions in the settings page.
• Changes for appending the .md content to system prompt.
• Collapsible Menu to enable or disable file and text instructions on the fly.
• Respective file system operations for creating and deleting files in .vscode/hai-instructions
• Respective error handling and message displays.
• Changed cline_mcp_settings.json to hai_mcp_settings.json

Type of Change

• 🐛 Bug fix (non-breaking change which fixes an issue)
• ✨ New feature (non-breaking change which adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to not work as expected)
• 📚 Documentation update

Pre-flight Checklist

• Changes are limited to a single feature, bugfix or chore (split larger changes into separate PRs)
• Tests are passing (npm test) and code is formatted and linted (npm run format && npm run lint)
• I have reviewed contributor guidelines

Screenshots

Additional Notes