fix: handle root directory startup error from Claude Desktop

- When started from Claude Desktop, working directory might be "/"
- Now defaults to user home directory if cwd is "/"
- Startup scripts change to script directory for consistency
- Simplified README to remove implementation details about PROJECT_ROOT

This fixes the "MCP_PROJECT_ROOT cannot be set to '/'" error
while maintaining security by preventing filesystem-wide access.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

run_gemini.sh

@@ -15,5 +15,8 @@ else
     PYTHON_EXEC="python3"
 fi
 
+# Change to script directory to ensure proper working directory
+cd "$SCRIPT_DIR"
+
 # Run the server
 exec "$PYTHON_EXEC" "$SCRIPT_DIR/server.py"