feat: Use dynamic terminal width detection for Rich console output

Use shutil.get_terminal_size() with fallback to 100 characters instead of auto-detecting narrow widths. This provides better traceback readability while being more adaptive than fixed width settings.

Co-authored-by: William Easton <strawgate@users.noreply.github.com>

src/fastmcp/cli/cli.py

@@ -26,12 +26,12 @@ from fastmcp.utilities.inspect import (
     format_info,
     inspect_fastmcp,
 )
-from fastmcp.utilities.logging import get_logger
+from fastmcp.utilities.logging import get_logger, get_terminal_width
 from fastmcp.utilities.mcp_server_config import MCPServerConfig
 from fastmcp.utilities.mcp_server_config.v1.environments.uv import UVEnvironment
 
 logger = get_logger("cli")
-console = Console()
+console = Console(width=get_terminal_width())
 
 app = cyclopts.App(
     name="fastmcp",

src/fastmcp/utilities/cli.py

@@ -231,5 +231,7 @@ def log_server_banner(
         expand=False,
     )
 
-    console = Console(stderr=True)
+    from fastmcp.utilities.logging import get_terminal_width
+
+    console = Console(stderr=True, width=get_terminal_width())
     console.print(Group("\n", panel, "\n"))

src/fastmcp/utilities/logging.py

@@ -1,12 +1,25 @@
 """Logging utilities for FastMCP."""
 
 import logging
+import shutil
 from typing import Any, Literal
 
 from rich.console import Console
 from rich.logging import RichHandler
 
 
+def get_terminal_width() -> int:
+    """Get terminal width using shutil.get_terminal_size() with fallback to 100.
+
+    Returns:
+        Terminal width in characters, defaulting to 100 if detection fails.
+    """
+    try:
+        return shutil.get_terminal_size().columns
+    except (OSError, ValueError):
+        return 100
+
+
 def get_logger(name: str) -> logging.Logger:
     """Get a logger nested under FastMCP namespace.
 
@@ -39,7 +52,7 @@ def configure_logging(
 
     # Only configure the FastMCP logger namespace
     handler = RichHandler(
-        console=Console(stderr=True),
+        console=Console(stderr=True, width=get_terminal_width()),
         rich_tracebacks=enable_rich_tracebacks,
         **rich_kwargs,
     )