feat: install Rich's global exception handler for improved error reporting

Added installation of Rich's global exception handler to route tracebacks to stderr instead of stdout. This change enhances error diagnostics by preventing mixing of normal output with error messages.

Author: pyq

src/mcpm/cli.py

@@ -7,6 +7,7 @@
 
 from rich.console import Console
 from rich.traceback import Traceback
+from rich.traceback import install as install_rich_traceback
 
 from mcpm.clients.client_config import ClientConfigManager
 from mcpm.commands import (
@@ -38,6 +39,10 @@
 # Setup Rich logging early - this runs when the module is imported
 setup_logging()
 
+# Install Rich's global exception handler to use stderr instead of stdout
+# This prevents Rich/rich-gradient from routing tracebacks to stdout
+install_rich_traceback(console=err_console, show_locals=True)
+
 # Custom context settings to handle main command help specially
 CONTEXT_SETTINGS: Dict[str, Any] = dict(help_option_names=[])