Create CLAUDE.md and AGENTS.md project guide files

[yankay]

Background

To help AI coding assistants (Claude Code, GitHub Copilot, Cursor, etc.) better understand the project structure and development conventions, we need standardized guide files in the repository root.

Goals

1. Review and update CLAUDE.md

CLAUDE.md already exists. Review and ensure it covers:

• Project overview and architecture
• Monorepo structure
• Tech stack
• Development commands
• Key protocols (Session Key, Gateway WS)
• Coding conventions
• Known issues and pitfalls
• Verify content is in sync with latest codebase

2. Create AGENTS.md

Create AGENTS.md as a universal AI agent guide file (compatible with GitHub Copilot Workspace, Codex, and similar tools). It should include:

• One-line project description
• Directory structure overview
• Build and test commands
• Code style and conventions (TypeScript strict, CSS Variables, Zustand state management, etc.)
• PR / Commit conventions
• Security guidelines (no committed secrets, no hardcoded credentials, etc.)
• Consistent with CLAUDE.md but formatted for different tools

Acceptance Criteria

• CLAUDE.md content is in sync with the current codebase
• AGENTS.md exists in the repository root
• No conflicting information between the two files
• AI assistants can correctly understand the project and generate code that follows conventions based on these files