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/main/runtime-events.ts

@@ -1,16 +1,17 @@
-type RuntimeInvalidationReason = 'account-health'
+type RuntimeInvalidationReason = 'account-health' | 'publish-task-lease'
 
 type RuntimeInvalidationListener = (event: {
   reason: RuntimeInvalidationReason
   at: number
   accountId?: string
+  taskId?: string
 }) => void
 
 const listeners = new Set<RuntimeInvalidationListener>()
 
 export function emitRuntimeInvalidated(
   reason: RuntimeInvalidationReason,
-  details: { accountId?: string } = {},
+  details: { accountId?: string; taskId?: string } = {},
 ): void {
   const event = {
     reason,