Implement MCP integration for AI agents and enhance sync functionality

- Added a new section in the README to document the integration of MCP (Model Context Protocol) for AI agents, detailing how to set up and use the `atlas_sync` tool.
- Introduced `McpStream` to manage WebSocket connections for real-time sync commands between the plugin and the MCP server.
- Enhanced the `App` component to initialize and manage the MCP stream, including handling sync commands and user confirmations.
- Updated the API to support WebSocket upgrades for the MCP stream, allowing for efficient communication with connected plugins.
- Improved the handling of sync commands, ensuring proper responses based on the current connection state and user selections.

These changes aim to facilitate programmatic syncs to Roblox Studio, improving the workflow for teams using AI agents.

README.md

@@ -191,6 +191,67 @@ Atlas includes a sync lock to prevent conflicts when multiple people work on the
 
 **Recommended team workflow:** One designated person syncs in persistent mode (one-shot disabled). Everyone else uses one-shot mode for quick, conflict-free previews.
 
+## MCP Integration (AI Agents)
+
+`atlas serve` automatically hosts an MCP (Model Context Protocol) server on the same port as the API. This lets AI agents like Cursor and Claude Code trigger syncs to Roblox Studio programmatically.
+
+### Available Tools
+
+| Tool | Description |
+|------|-------------|
+| `atlas_sync` | Sync filesystem changes to Studio. Auto-accepts if all changes are pre-selected by git. Blocks until the user accepts or rejects if there are unresolved changes. |
+
+### Adding to Cursor
+
+Create or edit `.cursor/mcp.json` in your project root:
+
+```json
+{
+  "mcpServers": {
+    "atlas": {
+      "url": "http://localhost:34873/mcp"
+    }
+  }
+}
+```
+
+If your project uses a custom port (via `servePort` in the project file), update the URL accordingly.
+
+### Adding to Claude Code
+
+```bash
+claude mcp add atlas --transport http http://localhost:34873/mcp
+```
+
+Or add it to your project-level config at `.claude/settings.json`:
+
+```json
+{
+  "mcpServers": {
+    "atlas": {
+      "type": "url",
+      "url": "http://localhost:34873/mcp"
+    }
+  }
+}
+```
+
+### How It Works
+
+1. Start `atlas serve` — the MCP server is available immediately
+2. The Studio plugin connects to the MCP stream in the background (retries every 5s)
+3. When an agent calls `atlas_sync`:
+   - If all changes are pre-selected by the git system, they are **auto-accepted** (fast-forward)
+   - If there are unresolved changes, the **Confirming page** appears in Studio for the user to review
+   - The agent blocks until the sync completes and receives a list of synced file paths with directions (`push`/`pull`)
+4. If the plugin is already connected in live sync mode, the tool returns immediately with a notice that sync is automatic
+
+### Requirements
+
+- `atlas serve` must be running
+- Roblox Studio must be open with the Atlas plugin installed
+- The plugin does **not** need to be manually connected — the MCP stream connects automatically
+
 ## File Formats
 
 ### Scripts