Set channel mode +r when a channel is registered

ChanServ sends FMODE to mark a registered channel +r (the m_services
c_registered mode), and -r on drop. Sourced from our server, which the
ircd requires for that mode, with a low TS so it applies to the existing
channel.

src/engine/mod.rs

@@ -922,16 +922,20 @@ mod tests {
         // Not identified yet: refused.
         assert!(notice(&to_cs(&mut e, "000AAAAAB", "REGISTER #room"), "must be identified"));
 
-        // Identify, then register.
+        // Identify, then register: sets +r on the channel.
         e.handle(NetEvent::Privmsg { from: "000AAAAAB".into(), to: "42SAAAAAA".into(), text: "IDENTIFY sesame".into() });
-        assert!(notice(&to_cs(&mut e, "000AAAAAB", "REGISTER #room"), "now registered"));
+        let out = to_cs(&mut e, "000AAAAAB", "REGISTER #room");
+        assert!(notice(&out, "now registered"));
+        assert!(out.iter().any(|a| matches!(a, NetAction::ChannelMode { channel, modes } if channel == "#room" && modes == "+r")), "register sets +r: {out:?}");
         assert!(notice(&to_cs(&mut e, "000AAAAAB", "INFO #room"), "alice"));
 
         // A different, unidentified user cannot drop it.
         e.handle(NetEvent::UserConnect { uid: "000AAAAAC".into(), nick: "bob".into() });
         assert!(notice(&to_cs(&mut e, "000AAAAAC", "DROP #room"), "founder"));
 
-        // The founder can.
-        assert!(notice(&to_cs(&mut e, "000AAAAAB", "DROP #room"), "dropped"));
+        // The founder can, which also clears +r.
+        let out = to_cs(&mut e, "000AAAAAB", "DROP #room");
+        assert!(notice(&out, "dropped"));
+        assert!(out.iter().any(|a| matches!(a, NetAction::ChannelMode { channel, modes } if channel == "#room" && modes == "-r")), "drop clears +r: {out:?}");
     }
 }

src/engine/service.rs

@@ -74,4 +74,12 @@ impl ServiceCtx {
             nick: nick.to_string(),
         });
     }
+
+    // Set channel modes from services, e.g. "+r" on a registered channel.
+    pub fn channel_mode(&mut self, channel: &str, modes: &str) {
+        self.actions.push(NetAction::ChannelMode {
+            channel: channel.to_string(),
+            modes: modes.to_string(),
+        });
+    }
 }