docs: add MCP one-liner explainer for new users (OD-739)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: 2 people

README.md

@@ -21,6 +21,8 @@
 
 GitMem is an [MCP server](https://modelcontextprotocol.io/) that gives your AI coding agent **persistent memory across sessions**. It remembers mistakes (scars), successes (wins), and decisions — so your agent learns from experience instead of starting from scratch every time.
 
+> **What's MCP?** [Model Context Protocol](https://modelcontextprotocol.io/) is how AI coding tools connect to external capabilities. GitMem is an MCP server — install it once and your agent gains persistent memory.
+
 Works with **Claude Code**, **Cursor**, **VS Code (Copilot)**, **Windsurf**, and any MCP-compatible client.
 
 ## Quick Start

apps/docs/content/docs/getting-started/index.mdx

@@ -12,6 +12,8 @@ GitMem gives your AI coding agents institutional memory — the ability to learn
 - **Node.js 18+** (for `npx gitmem-mcp init`)
 - An MCP-compatible client: [Claude Code](https://claude.com/claude-code), [Claude Desktop](https://claude.ai/download), or [Cursor](https://cursor.sh)
 
+> **What's MCP?** [Model Context Protocol](https://modelcontextprotocol.io/) is how AI coding tools connect to external capabilities like memory, databases, and APIs. GitMem is an MCP server — install it once and your agent gains persistent memory. No plugins, no extensions, just a standard protocol.
+
 ## Quick Start (30 seconds)
 
 ```bash