feat: add MCP search service

mcp/README.md

@@ -0,0 +1,39 @@
+# OpenIsle MCP Server
+
+This package provides a [Model Context Protocol](https://github.com/modelcontextprotocol) (MCP) server that exposes the OpenIsle
+search capabilities to AI assistants. The server wraps the existing Spring Boot backend and currently provides a single `search`
+tool. Future iterations can extend the server with additional functionality such as publishing new posts or moderating content.
+
+## Features
+
+- 🔍 **Global search** — delegates to the existing `/api/search/global` endpoint exposed by the OpenIsle backend.
+- 🧠 **Structured results** — responses include highlights and deep links so AI clients can present the results cleanly.
+- ⚙️ **Configurable** — point the server at any reachable OpenIsle backend by setting environment variables.
+
+## Local development
+
+```bash
+cd mcp
+python -m venv .venv
+source .venv/bin/activate
+pip install -e .
+openisle-mcp --transport stdio  # or "sse"/"streamable-http"
+```
+
+Environment variables:
+
+| Variable | Description | Default |
+| --- | --- | --- |
+| `OPENISLE_BACKEND_URL` | Base URL of the Spring Boot backend | `http://springboot:8080` |
+| `OPENISLE_BACKEND_TIMEOUT` | Timeout (seconds) for backend HTTP calls | `10` |
+| `OPENISLE_PUBLIC_BASE_URL` | Optional base URL used to build deep links in search results | *(unset)* |
+| `OPENISLE_MCP_TRANSPORT` | MCP transport (`stdio`, `sse`, `streamable-http`) | `stdio` |
+| `OPENISLE_MCP_SSE_MOUNT_PATH` | Mount path when using SSE transport | `/mcp` |
+| `FASTMCP_HOST` | Host for SSE / HTTP transports | `127.0.0.1` |
+| `FASTMCP_PORT` | Port for SSE / HTTP transports | `8000` |
+
+## Docker
+
+A dedicated Docker image is provided and wired into `docker-compose.yaml`. The container listens on
+`${MCP_PORT:-8765}` and connects to the backend service running in the same compose stack.
+