feat: add fonts utility for listing available system fonts

[joshukraine]

Feature Request

Add a fonts command-line utility to easily list and search available system fonts.

Motivation

Currently, to check available fonts for terminal configuration, users need to remember complex fc-list commands with various pipes and filters. A simple fonts utility would improve the developer experience.

Proposed Solution

Create a script at bin/fonts that provides an intuitive interface for font discovery:

# List all fonts
fonts

# List monospace fonts (useful for terminals)
fonts -m
fonts --mono

# List Nerd Fonts (for icon support)
fonts -n
fonts --nerd

# Search fonts by pattern
fonts cascadia
fonts -m jet    # monospace fonts matching "jet"

Implementation Details

• Standalone bash script in bin/ directory
• Uses fc-list under the hood with appropriate filters
• Supports options for monospace (-m) and Nerd Fonts (-n)
• Accepts optional search pattern
• Includes built-in help (-h, --help)
• Clean, sorted, deduplicated output

Benefits

1. Discoverability: Simple command name that's easy to remember
2. Flexibility: Filter by font type and search pattern
3. Terminal-focused: Special support for monospace and Nerd Fonts
4. Self-documenting: Built-in help with examples

Integration

Once implemented, update configuration file comments (e.g., in ghostty config) to reference this utility instead of raw fc-list commands.

Reference Implementation

See scratchpads/notes/fonts-utility-20250128.md for the full implementation.

[joshukraine]

One thing to note: in Ghostty, available mono fonts can be listed with ghostty +list-fonts.

Ref: https://ghostty.org/docs/config/reference#font-family