How this table is made

Each provider site publishes two things for its own purposes: the markdown twin of its report, which carries a patterns: block in its front-matter, and the claim index its own search pane matches against. bin/sync-providers.py reads both and writes data/providers.yml; the build reads that file and never touches the network.

That is deliberate in three ways:

• A sync is a dated act. The date is printed under the table, and CI does not silently refresh it. If the data is stale, the staleness is visible rather than guessed at.
• The build is reproducible and offline. A site whose build depends on the network is a site that breaks when somebody else deploys.
• There is one source of truth per fact, and it is not here. A hub that maintains its own table of other people's properties will drift from them, and it will be the hub that is wrong.

bin/sync-providers.py --check reports drift without changing anything, which is the form CI could take if this ever needs to be automatic.