Add comprehensive GitHub Copilot instructions for ComfyUI ES Wrapper development

[Copilot]

This PR adds a comprehensive .github/copilot-instructions.md file that provides GitHub Copilot coding agents with detailed, validated instructions for working effectively in the ComfyUI ES Wrapper codebase.

Key Features

Complete Development Workflow

• Step-by-step bootstrap instructions with exact commands
• Validated installation process including required environment variables
• Build, test, and validation procedures with accurate timing information

Critical Dependencies Handling

• Documents the required PLAYWRIGHT_SKIP_BROWSER_DOWNLOAD=1 environment variable for installation
• Explains npm vs pnpm usage (npm is required despite pnpm lockfiles)
• Covers security audit procedures and dependency management

Validated Command Reference
All commands have been thoroughly tested and validated:

• npm run typecheck - TypeScript validation (~2 seconds)
• npm run build - Library build with dual ESM/CJS output (~3 seconds)
• npm run dev - Watch mode development
• Import validation using Node.js ES modules

Project Structure Guide

• Complete source directory layout with explanations
• Key files and their purposes (editor, components, adapters, types, utils)
• Common editing patterns and best practices
• Build output structure and exports

Comprehensive Validation Scenarios

• Build verification procedures
• Import testing commands that confirm all 8 expected exports
• Manual testing guidelines for React/Vue adapters
• Pre-commit validation checklist

The instructions follow the imperative tone requirement and include explicit "NEVER CANCEL" warnings with appropriate timeout values for all build operations. Every command and procedure documented has been manually validated to ensure reliability.

Fixes #3.

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💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.

[Copilot]

@zinigor 👋 This repository doesn't have Copilot instructions. With Copilot instructions, I can understand the repository better, work faster and produce higher quality PRs.

I can generate a .github/copilot-instructions.md file for you automatically. Click here to open a pre-filled issue and assign it to me. I'll write the instructions, and then tag you for review.