Clippy sweep: clean across the workspace

- Box the oversized enum variants (Event::AccountRegistered, gossip
  Msg::Entry) so small events aren't sized to a full Account; serde is
  transparent so the wire/log format is unchanged.
- Use the configured server description in the SERVER line (it was
  hardcoded and the config field went unread).
- Derive the ChanServ SET label from the ChanSetting (drops toggle's 8th
  arg); rename inspircd from_us -> sourced.
- allow the two framework-idiom lints with rationale (tonic's Status in
  authorize; the guest-rename handler's inherent arg count).
- Auto-fixed map_or/contains/split_once style lints.

src/engine/mod.rs

@@ -1916,7 +1916,7 @@ mod tests {
             name: "alice".into(), password_hash: "OTHER".into(), email: None,
             ts: 0, home: "peer".into(), scram256: None, scram512: None, certfps: vec![], verified: true, ajoin: vec![], suspension: None, memos: vec![], greet: String::new(), vhost: None, vhost_request: None,
         };
-        let entry = LogEntry::for_test("peer", 0, 1, db::Event::AccountRegistered(winner));
+        let entry = LogEntry::for_test("peer", 0, 1, db::Event::AccountRegistered(Box::new(winner)));
         e.gossip_ingest(entry).unwrap();
 
         // The local session is logged out and its orphaned channel is dropped.