huskies: merge 1144 story Gateway trampoline-restart: detached helper survives the gateway's own death

server/src/chat/transport/matrix/bot/context.rs

@@ -99,6 +99,11 @@ pub struct BotContext {
     /// each event is processed at most once. Insert the event ID before any
     /// side-effecting work; return early if the insert returns `false`.
     pub handled_incoming_event_ids: Arc<TokioMutex<SeenEventIds>>,
+    /// In gateway mode: the port the gateway is listening on.
+    ///
+    /// Used by the "rebuild gateway" command to construct the health-check URL
+    /// passed to the trampoline.  `None` in standalone single-project mode.
+    pub gateway_port: Option<u16>,
 }
 
 impl BotContext {
@@ -293,6 +298,7 @@ mod tests {
             handled_incoming_event_ids: Arc::new(TokioMutex::new(SeenEventIds::new(
                 SEEN_EVENT_IDS_CAP,
             ))),
+            gateway_port: None,
         }
     }