fix(restore): recover inactive tabs after hydration failure

Continue restoring saved workspace state when the initial session-list request fails transiently. The direct saved-session hydration path can recover after reconnect, preserving selection, runtime markers, scroll position, and the original tab order instead of appending the unresolved workspace after the active tab.

This behavior is shared by Electron and Tauri. Validated with the UI typecheck, production build, 65 restoration and reconciliation tests, and 13 instance runtime authority tests.

Author: pascalandr

packages/ui/src/lib/hooks/use-app-session-restore.ts

@@ -27,6 +27,7 @@ import {
 } from "../../stores/sessions"
 import { messageStoreBus, type MessageScrollSnapshotSeed } from "../../stores/message-v2/bus"
 import { hydrateWorkspacePromptState } from "../../stores/app-session-prompt-hydration"
+import { waitForSettledPrerequisite } from "../trailing-resync"
 const log = getLogger("actions")
 const MESSAGE_SCROLL_SCOPE = "message-stream"
 const NO_SESSION_DRAFT_SESSION_ID = "__no_session_draft__"
@@ -153,7 +154,11 @@ async function restoreTabs(context: RestoreContext): Promise<void> {
         const created = creation?.reused === false
         if (created) createdId = id
         try {
-          await runAbortable(() => waitForInstanceInitialSessionHydration(id), { signal: operationSignal })
+          // A reconnect can recover the list; saved IDs still restore directly after an initial failure.
+          await runAbortable(
+            () => waitForSettledPrerequisite(waitForInstanceInitialSessionHydration(id)),
+            { signal: operationSignal },
+          )
           const tabId = getInstanceAppTabId(id)
           const isCurrentBinding = () => capture.hasRestoredTabBinding(match.tabIndex, tabId)
           if (!isCurrentBinding()) return id