fix(browser): keep snapshot ids valid after an observed action is refused

An observed click refused before dispatch (for example, covered by an overlay)
never starts its observation, yet it invalidated every id in the snapshot, so
the agent could not click the overlay's own close button without re-observing.
A failed observed action with no dispatched outcome now only cancels an
in-flight capture, which clears the refs itself when it starts.

Author: waleedlatif1

apps/desktop/src/main/browser-agent/driver.test.ts

@@ -3425,6 +3425,24 @@ describe('credential protection', () => {
     expect(second).not.toMatchObject({ result: { notices: expect.anything() } })
   })
 
+  it('keeps element ids valid when an observed action is refused before dispatch', async () => {
+    const contents = await openPage()
+    respondWith(contents, { clickElement: { error: 'obstructed', blocker: 'IMG' } })
+
+    const refused = await driver.executeTool('chat-test', 'browser_click', {
+      elementId: 0,
+      observe: {},
+    })
+    respondWith(contents, {})
+    const retried = await driver.executeTool('chat-test', 'browser_click', { elementId: 0 })
+
+    expect(refused).toEqual({
+      ok: false,
+      error: expect.stringContaining('That element is covered by IMG'),
+    })
+    expect(retried).toMatchObject({ ok: true, result: { dispatched: true } })
+  })
+
   it('invalidates element ids when the active tab changes', async () => {
     await openPage()
     await driver.executeTool('chat-test', 'browser_open_tab', {})

apps/desktop/src/main/browser-agent/driver.ts

@@ -313,6 +313,14 @@ function createDriverScopeState(): DriverScopeState {
 function invalidateSnapshot(state = driverScopeState()): void {
   state.snapshotTabId = null
   state.snapshotTargets.clear()
+  cancelPendingSnapshotCapture(state)
+}
+
+/**
+ * Keeps the current refs but stops any in-flight capture from committing its own. A capture
+ * clears the refs when it starts, so this is all a failed action with a pending observation needs.
+ */
+function cancelPendingSnapshotCapture(state: DriverScopeState): void {
   state.snapshotCaptureEpoch++
 }
 
@@ -5002,7 +5010,10 @@ export async function executeTool(
           try {
             observedResult = await guardedExecution
           } catch (error) {
-            if (!actionOutcome) throw error
+            if (!actionOutcome) {
+              if (params.observe !== undefined) cancelPendingSnapshotCapture(state)
+              throw error
+            }
             invalidateSnapshot(state)
             observedResult =
               actionOutcome.status === 'pending'
@@ -5049,12 +5060,7 @@ export async function executeTool(
       // The watchdog cannot cancel an in-flight renderer promise. Invalidate its
       // capture token before releasing the queue so a late snapshot cannot
       // overwrite refs belonging to a newer tab or snapshot.
-      if (
-        tool === 'browser_snapshot' ||
-        tool === 'browser_open_url' ||
-        tool === 'browser_find' ||
-        params.observe !== undefined
-      ) {
+      if (tool === 'browser_snapshot' || tool === 'browser_open_url' || tool === 'browser_find') {
         invalidateSnapshot(state)
       }
       const message = String(sanitizeBrowserResult(getErrorMessage(error), undefined, 0, 'error'))