banner: "once" behaves identically to "always"

[urda]

Version

Copilot CLI 1.0.70 on macOS.

Reproduction

Set the user settings file to:

{
  "banner": "once"
}

Then:

1. Start copilot. The animated banner appears.
2. Exit Copilot.
3. Start copilot again. The animated banner appears again.

Expected behavior

"banner": "once" should display the animated startup banner only once, then suppress it on subsequent startups.

Actual behavior

The animated banner appears every time Copilot starts. It behaves the same as "banner": "always".

Related observations

• "banner": "never" correctly suppresses the startup banner.
• copilot --banner correctly forces the banner to show.
• Removing the banner setting also repeats the banner at every startup, despite the documented default being "once".

Additional technical note

In the 1.0.70 packaged TUI, "never" is handled as the sole disabled case. Both "once" and "always" follow the animation path, and the first-launch state is not used to suppress a configured "once" banner value.