Fix log level validation error preventing server startup

- Add import os statement
- Set LOG_LEVEL environment variable to 'INFO' by default
- Pass explicit log_level='INFO' parameter to FastMCP constructor

This fixes the ValueError: Invalid log level: info. Expected one of: ['DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL']
that prevents the server from starting when FastMCP receives lowercase log levels.

Author: Mgabr90

pymupdf4llm_mcp/app.py

@@ -1,11 +1,14 @@
+import os
 from pathlib import Path
 from typing import Annotated, Any
 
 import pymupdf4llm
 from mcp.server.fastmcp import FastMCP
 from pydantic import Field
 
-mcp = FastMCP("pymupdf4llm-mcp")
+# Fix: Set environment variable and explicit log level to prevent validation error
+os.environ.setdefault('LOG_LEVEL', 'INFO')
+mcp = FastMCP("pymupdf4llm-mcp", log_level='INFO')
 
 
 @mcp.tool(
@@ -73,4 +76,4 @@ def convert_pdf_to_markdown(
         return {
             "error": f"Failed to convert PDF to markdown: {e!s}",
             "success": False,
-        }
+        }