Split Provider Usage footer test by behavior

[ymichael]

Human comments

What was wrong

The Provider Usage footer coverage put plugin import/registration, the content-script preload and focus listener lifecycle, disclosure rendering, two Radix machine-menu sessions, provider mouse and keyboard navigation, disconnected state, dismiss, manual refresh, and disposal inside one asynchronous test with the default 5-second budget. Package-shard concurrency and Vitest worker oversubscription made that serial UI sequence slow enough to expose the test architecture: the unchanged test reproduced at 6.610 seconds under bounded Intel contention and timed out at 5 seconds. The CI failure was therefore not a deterministic regression in PR #3449, and scheduler contention was the trigger rather than the root cause.

What changed

plugins/provider-usage/app.test.tsx now loads and captures the plugin registration once outside test clocks, reuses one response fixture, and divides coverage into registration, content-script focus refresh, disconnected/manual refresh, and connected machine/provider interaction scenarios. Content-script disposal is protected by finally. The disconnected case starts from the active Intel machine, removing a second Radix menu lifecycle while the connected case still proves all machines are aggregated and exercises machine selection plus provider mouse and keyboard navigation. No assertions were disabled, no timeout was increased, and there are no wire, CLI, or documentation changes.

How you verified

• Before: on enrolled Intel host host_nwqfteeqz4, a warmed run with 12 bounded CPU competitors reproduced the exact failure: 6.610 seconds and Test timed out in 5000ms.
• After: the same 12-worker warmed stress passed all four scenarios; the slowest scenario was 833 ms.
• After: five fresh focused iterations under 12 CPU competitors passed 20/20 scenario executions; the slowest scenario was 1.202 seconds.
• pnpm exec turbo run test --filter=bb-plugin-provider-usage — 3 files and 7 tests passed.
• pnpm exec turbo run typecheck --filter=bb-plugin-provider-usage — passed.
• pnpm exec turbo run build --filter=bb-plugin-provider-usage — passed the package's available upstream generator tasks; this package has no build script.
• bb plugin build from plugins/provider-usage — emitted validated server and app bundles.
• Every test/build/load command ran in a bounded process group; teardown and the final process scan found no surviving Vitest, Turbo, plugin-build, or load workers.

AGENT GENERATED