v0.5.0

What's new

• L402 paywall support — ln.l402.create_challenge(), ln.l402.verify(), ln.l402.pay() (sync + async)
• Get/watch by payment hash — ln.invoices.get() and ln.payments.get() now accept int | str
• Removed ln.keys.list() — server endpoint removed (key listing is a local CLI operation)

Breaking changes

• keys.list() removed from both KeysResource and AsyncKeysResource
• ApiKeyResponse type removed