useIsAirdrop

Ask the canonical factory whether it created candidate - the genuineness check.

Run this before trusting an address a user pasted, a link carried, or an indexer returned. A look-alike instance with the same ABI, the same events and a pool the attacker controls is cheap to deploy, and nothing readable at the instance tells it apart. A claim against one succeeds and delivers nothing.

The factory this asks is the one resolved from src/core/addresses.ts for the connected chain, which is what makes the answer worth anything: an instance that names its own factory names a fake one.

Only a `true` is cached. The registry is append-only, so a true can never become false and is safe to hold forever. A false is not stable: the address can be created later by another tab, another service, or the headless client, none of which reaches this hook's invalidations - so caching it would serve a stale false negative indefinitely and, for a security check, in the direction that blocks a legitimate claim. Negative answers therefore stay fresh and refetch normally. Override either with query.staleTime.

The `address` override is the trust root. Like every factory hook this accepts address, and useMemoAirdropFactoryClient prefers it over src/core/addresses.ts. That is what makes the hook usable on a local chain, but it also means an attacker-supplied factory address would answer true for its own look-alike. Pass address only from a source you trust at least as much as the registry; when in doubt, omit it.