Fix ANSI character handling in rich Panel displays

[ccmitchellusa]

Summary

This PR fixes ANSI character handling and text wrapping issues in rich Panel displays throughout mcp-cli. The fixes ensure that:

• ANSI escape sequences (colors, formatting) are preserved and displayed correctly
• ASCII art and charts maintain proper structure without truncation
• Regular text content wraps properly across multiple lines without ellipses
• All panel types (Tool results, Streaming, Assistant) handle both content types consistently

Changes Made

Core Formatting (src/mcp_cli/tools/formatting.py)

• Added format_content_with_ansi_support() helper function for consistent ANSI handling
• Enhanced display_tool_call_result() to detect and properly format ANSI/ASCII content
• Fixed text wrapping to use overflow="fold" instead of ellipses mode
• Added zero-width space character cleaning for better display

Streaming Handler (src/mcp_cli/chat/streaming_handler.py)

• Fixed ANSI content detection and handling in _create_display_content()
• Resolved variable scope error that caused streaming failures
• Applied consistent text wrapping approach for both ANSI and regular content

UI Manager (src/mcp_cli/chat/ui_manager.py)

• Updated print_assistant_response() to handle ANSI content properly
• Ensured fallback text rendering uses proper wrapping without ellipses

Command Tools (src/mcp_cli/commands/tools_call.py)

• Fixed function signature bug in tool result display

Testing

• Verified ANSI charts (from plotext_plus MCP server) display correctly with preserved colors
• Confirmed long text content wraps across multiple lines without ellipses
• Tested streaming functionality works without errors
• Validated both vertical and horizontal orientations work properly

Technical Details

The key insight was distinguishing between content types:

• ANSI/ASCII art: Uses Text.from_ansi() with no_wrap=True to preserve structure
• Regular text: Uses Text() with overflow="fold", no_wrap=False for proper wrapping

Box-drawing characters are detected to identify ASCII art: {'┌', '┐', '└', '┘', '├', '┤', '┬', '┴', '┼', '│', '─', '█', '▄', '▀', '▌', '▐'}