Avoid returning failure after initiating a channel #1143

open_channel_inner creates a channel before persisting the peer's reconnection information. If that persistence fails, the API returns Error::PersistenceFailed even though the channel is already live and opening messages may have been sent. A caller retrying the apparent failure can therefore open a second channel and repeat any push amount. The affected ordering is in src/lib.rs:1418-1449 at main 1dea48a5ea06e5af2eabbf0633b32aee3338bd6c; an ordinary transient peer-store write failure is sufficient.

Make the result accurately reflect whether channel opening was initiated: persist the required peer information before creating the channel, or return the initiated channel's ID and report the persistence problem separately. Add a regression that fails only the peer-store write and verifies the API cannot report an ordinary failed initiation while leaving a live channel; include successful initiation and retry controls. Fixing peer-store cache rollback alone does not fix this ordering issue. No regression test or production patch was run during triage.