f Document legacy for-hash events

Clarify that v0.7-or-earlier for-hash invoices can still emit
PaymentClaimable after upgrade regardless of the new config flag.

Co-Authored-By: HAL 9000

Author: tnull

src/event.rs

@@ -208,6 +208,9 @@ pub enum Event {
 	/// holder of a valid invoice generated by this node tie up inbound HTLC slots and grow the
 	/// persisted event queue until the payment is claimed, failed, or times out.
 	///
+	/// Any `_for_hash` invoices created with LDK Node v0.7 or prior can still emit this event
+	/// after upgrade and must be claimed or failed back regardless of the config setting.
+	///
 	/// [`claim_for_id`]: crate::payment::Bolt11Payment::claim_for_id
 	/// [`fail_for_id`]: crate::payment::Bolt11Payment::fail_for_id
 	/// [`Config::manually_handle_unknown_bolt11_payments`]: crate::config::Config::manually_handle_unknown_bolt11_payments