fix(angular-query-experimental): keep the SSR pending task held from fetch start until the result is applied

.changeset/angular-ssr-pending-task-coverage.md

@@ -0,0 +1,5 @@
+---
+'@tanstack/angular-query-experimental': patch
+---
+
+Keep the SSR pending task registered from fetch start until the query result is applied to the result signal. Previously the task was registered and released inside the subscriber callback: registration waited for the first notifyManager delivery turn (`setTimeout(0)`), and release ran one statement before the result signal write. With zoneless change detection, `ApplicationRef.whenStable()` could resolve in either gap, so Angular SSR serialized HTML rendered from stale optimistic state even though the fetch had completed.

packages/angular-query-experimental/src/__tests__/inject-query.test.ts

@@ -772,6 +772,10 @@ describe('injectQuery', () => {
       // Synchronize pending effects
       TestBed.tick()
 
+      // The in-flight fetch now holds a pending task, so stability requires the
+      // notification turn and the change detection it schedules to run first
+      await vi.advanceTimersByTimeAsync(0)
+      TestBed.tick()
       const stablePromise = app.whenStable()
       await stablePromise
 
@@ -817,6 +821,10 @@ describe('injectQuery', () => {
       enabledSignal.set(true)
       TestBed.tick()
 
+      // The in-flight fetch now holds a pending task, so stability requires the
+      // notification turn and the change detection it schedules to run first
+      await vi.advanceTimersByTimeAsync(0)
+      TestBed.tick()
       await app.whenStable()
       expect(query.status()).toBe('success')
       expect(query.data()).toBe('sync-data-1')
@@ -841,6 +849,10 @@ describe('injectQuery', () => {
       // Synchronize pending effects
       TestBed.tick()
 
+      // The in-flight fetch now holds a pending task, so stability requires the
+      // notification turn and the change detection it schedules to run first
+      await vi.advanceTimersByTimeAsync(0)
+      TestBed.tick()
       await app.whenStable()
       expect(query.status()).toBe('success')
       expect(query.data()).toBe('sync-data-1')