Settings -> Trust is now functional, not read-only. useSetTrustProvider
publishes a kind-10040 designation for a custom provider (npub or 64-hex +
wss relay, the five 30382:<type> rows) and can clear it to fall back to the
community provider. The card validates input, prompts the signer, and
invalidates the provider + assertion queries so scores refresh. Docs
updated.
