docs: add root CLAUDE.md and fix AGENTS.md typo

[Zandereins]

Description

This repo already uses Claude Code (via claude.yml workflow and .mcp.json), but has no root CLAUDE.md to guide it. This PR adds one, plus fixes a typo in the existing AGENTS.md.

Changes

1. Root CLAUDE.md — Covers the full monorepo context:

• Monorepo structure overview (7 servers, 4 TypeScript + 3 Python)
• Build, test, and lint commands for both stacks (npm/vitest for TS, uv/pytest/pyright for Python)
• Code style conventions (extracted from existing AGENTS.md + package configs)
• Contributing guidelines summary (what's accepted vs. not)
• CI/CD pipeline overview (dynamic package detection matrix strategy)
• MCP protocol reference pointers (schema repo + docs MCP server)

2. Fix typo in src/everything/AGENTS.md

• start:stremableHttp → start:streamableHttp (matches actual script name in package.json)

Why

Anyone using Claude Code on this repo (including the claude.yml Action) currently gets no project context beyond what it reads from source files. The CLAUDE.md gives it immediate awareness of:

• Which servers are TypeScript vs. Python (and therefore which build/test commands to use)
• The correct test framework (vitest, not jest)
• The correct Python toolchain (uv, not pip)
• Contributing rules (no new servers, bug fixes welcome)
• Code style expectations

This is especially useful for the Claude Code GitHub Action which already handles @claude mentions on issues and PRs.

Server Details

• Server: all (root-level documentation)
• Changes to: documentation only

Motivation and Context

The repo has a claude.yml workflow and .mcp.json but no CLAUDE.md to provide project context. The existing AGENTS.md in src/everything/ only covers that one server. Contributors and the Claude Code Action benefit from monorepo-wide context.

How Has This Been Tested?

• Verified all build/test commands against package.json and pyproject.toml files
• Verified code style guidelines against existing AGENTS.md and actual source code
• Confirmed start:streamableHttp is the correct script name (not stremableHttp)

Types of changes

• Documentation update

Checklist

• I have read the MCP Protocol Documentation
• My changes follows MCP security best practices
• I have updated the server's README accordingly
• I have tested this with an LLM client
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have documented all environment variables and configuration options