Add Reading Lists Feature

This PR introduces a comprehensive reading lists feature to allowing users to organize books into lists for example: Top 50 Classics, or books I want to read.

Reading List Management

• Create lists with names and descriptions
• View all lists with progress indicators and statistics
• View specific list contents showing read/unread status
• Statistics showing completion progress across all lists

Import Books Lists from CSV

• Create lists during import with --name and --description flags
• Import to existing lists using --id flag
• Flexible CSV format supporting Title, Author, Pub Year, Pages, Genre

Download example lists created in data/ directory

• data/lists-classics.csv - Top 50 Classics
• data/lists-horror.csv - Top 50 Horror
• data/lists-sci-fi.csv - Top 50 Sci-fi

Import an example using: libro list import --name "Top 50 Classics" lists-classics.csv

List Usage Examples

  # Create and populate a list in one command
  libro list import books.csv --name "Sci-Fi Classics" --description "Must-read science fiction"

  # View all lists with progress
  libro list show

  # Add books interactively
  libro list add 1

  # Manage lists
  libro list edit 1 --name "Updated Name"
  libro list stats

Additional Improvements

• Removed genre restrictions - now accepts any string instead of just "fiction/nonfiction"