feat(desktop): refresh publish tasks instantly on lease activation

Emit a 'publish-task-lease' runtime invalidation event whenever the
scheduler activates a publish task, and have PublishManagementView
listen for it to trigger an immediate refresh. The view also switches
to a 5s active-task poll only while a task is in_progress, replacing
the unconditional 20s timer.

apps/desktop-client/src/preload/bridge.ts

@@ -145,11 +145,21 @@ const desktopBridge = {
     setWindowMode: (mode: 'login' | 'main', request?: WindowModeRequest) =>
       ipcRenderer.invoke('desktop:set-window-mode', mode, request) as Promise<null>,
     onRuntimeInvalidated: (
-      listener: (event: { reason: 'account-health'; at: number; accountId?: string }) => void,
+      listener: (event: {
+        reason: 'account-health' | 'publish-task-lease'
+        at: number
+        accountId?: string
+        taskId?: string
+      }) => void,
     ) => {
       const wrapped = (
         _event: IpcRendererEvent,
-        payload: { reason: 'account-health'; at: number; accountId?: string },
+        payload: {
+          reason: 'account-health' | 'publish-task-lease'
+          at: number
+          accountId?: string
+          taskId?: string
+        },
       ) => {
         listener(payload)
       }