docs: adding repo level claude.md

[rmad17]

Added

• doc: Added CLAUDE.md as the single source of truth for AI-agent guidance, including persona, working principles, project structure, repo boundaries, and security considerations
• doc: Added AGENTS.md to import CLAUDE.md so Claude Code, Codex CLI, Gemini CLI, and other compatible tools load the repo conventions
• doc: Added references/ docs for code style, testing, commands, pitfalls, git workflow, and docs-update guidance

Changed

• doc: Centralized AI-agent instructions around tracked references/ files instead of untracked docs/ output
• doc: Documented always-do, ask-first, and never-do boundaries to reduce incorrect agent assumptions in this repo