feat(ws): consume gateway change events (issue #784) (#837)

* feat(ws): consume gateway change events (cron/sessions/platforms/pairing) for targeted refresh (issue #784)

* test(chat): complete catch-all request stub — kill frozen-collector capture race (slash-focus flake, 4645a2b CI)

---------

Co-authored-by: M57 <hy4ri@users.noreply.github.com>

app/src/main/java/com/m57/hermescontrol/ui/sessions/SessionsViewModel.kt

@@ -10,7 +10,9 @@ import com.m57.hermescontrol.data.model.SessionSearchResult
 import com.m57.hermescontrol.data.remote.ApiClient
 import com.m57.hermescontrol.data.remote.NetworkResult
 import com.m57.hermescontrol.data.remote.safeApiCall
+import com.m57.hermescontrol.data.ws.ChangeEvents
 import com.m57.hermescontrol.ui.common.ToastHost
+import com.m57.hermescontrol.ui.common.refreshOnChange
 import com.m57.hermescontrol.ui.common.safeLaunchLoad
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.delay
@@ -62,6 +64,31 @@ class SessionsViewModel :
     private var loadJob: Job? = null
     private var statsJob: Job? = null
 
+    init {
+        // Issue #784: gateway broadcasts sessions.changed — refresh the list
+        // silently (no spinner, no selection reset) instead of blind polling.
+        refreshOnChange(
+            eventType = ChangeEvents.SESSIONS,
+            apiCall = {
+                safeApiCall {
+                    ApiClient.hermesApi.getSessions(
+                        limit = PAGE_SIZE,
+                        offset = 0,
+                        order = "recent",
+                    )
+                }
+            },
+            onSuccess = { data ->
+                _uiState.update {
+                    it.copy(
+                        sessions = data.sessions.orEmpty(),
+                        total = data.total,
+                    )
+                }
+            },
+        )
+    }
+
     /** Page size sent to the server — matches the default the gateway uses. */
     private companion object {
         const val PAGE_SIZE = 20