CLI usage examples in README don't match actual CLI interface

[monneyboi]

Problem

The README and CLAUDE.md show:

worldgraph extract                               # data/articles/ → data/graphs/
worldgraph match                                 # data/graphs/  → data/matched.json

But the actual CLI (cli.py) requires explicit file paths and output flags:

worldgraph extract <article_files...> -o <output_dir>
worldgraph match <graph_files...> -o <output_file>

The documented commands would fail with missing argument errors.

Suggested fix

Update the README/CLAUDE.md examples to show the actual invocation, e.g.:

worldgraph extract data/articles/*.json -o data/graphs/
worldgraph match data/graphs/*.json -o data/matched.json