First provider is not selected

[davidbrochart]

When pressing the down arrow key in the providers, OpenAI is not selected:

Screencast.From.2026-07-28.11-05-38.mp4

[ShreyanshVaibhaw]

Reproduced this in a Textual test harness and traced the cause.

Driving the picker (/login → API key → provider list) and inspecting the ListView state:

initial : index=None  highlighted=no   first3_classes=[[], [], []]
1x down : index=1  name=anthropic      <- first press lands on the SECOND provider
2x down : index=2  name=google

So the first provider (openai) is never reachable with the down key, which matches the video.

Root cause: LoginProviderPickerScreen._refresh_provider_list populates the list and then sets the index in the same synchronous pass:

provider_list.clear()
provider_list.extend([...])
provider_list.index = 0 if self.visible_providers else None

clear()/extend() are mount operations that complete asynchronously, so at the moment index = 0 is assigned the ListView still has no children and the reactive validates the value straight back to None. Nothing is highlighted when the picker opens (note the empty class lists above - no -highlight on any child), and the first arrow-down therefore moves off None to the second row rather than selecting the first.

Proof that the assignment itself is fine once the children exist - calling the same refresh again after mount works correctly:

after re-refresh (children exist): index=0  name=openai  highlighted=yes

I also see the initial index read back as 0 on some runs but still with no -highlight class rendered, so the symptom is timing-dependent in exactly the way an unawaited mount would be.

Fix direction: apply the index after the mount settles rather than in the same pass - either await the AwaitMount returned by extend() (making the refresh async) or schedule the assignment with call_after_refresh. The same populate-then-index-immediately pattern appears in several other pickers in app.py (session, prompt template, tools, skills), so they are likely affected too; I'd fix the reported provider picker first and can follow up on the rest separately.

I'd like to take this one. Happy to include a regression test that asserts the first entry is highlighted on open and that one down press lands on the second.