fix(eve): close facade browser resources

[shrey150]

why

This is PR 2 of the facade-close stack and depends on #2788.

The shared facade now propagates browser.close() to a host lifecycle callback, but Eve owns additional state that core cannot clean up generically: a keep-alive Browserbase session, its persisted session ID, reconnect/recovery decisions, and the currently cached facade tools. Eve must consume the signal at that ownership boundary.

Before this change, model-authored await browser.close() could return successfully while Eve retained the same facade and persisted Browserbase session. A later call could reuse authentication/cookie state from a browser the agent believed it had closed.

what changed

• Eve detaches the current facade before cleanup and serializes cleanup with later resource creation.
• Explicit close attempts both Stagehand and browser cleanup, then uses the shared Browserbase SDK release helper.
• Persisted ownership is cleared only after release succeeds; an ambiguous or failed release is marked suspect and surfaced.
• A later tool call creates fresh resources instead of reusing the closed facade.
• A model-code error does not poison the operation queue or discard a healthy browser.
• Initialization cleanup captures Browserbase release before Stagehand.create(); if local close fails, release is attempted immediately and persisted ownership is either cleared or retained for retry.
• Failed explicit release uses the shared typed BrowserbaseSessionReleaseError.
• Focused tests cover successful close/fresh creation, failed release reporting, local browser-close failure, persisted-ID clearing, and initialization cleanup.

behavior before and after

Eve lifecycle	Before	After
await browser.close()	Returns while retaining Eve-owned resources.	Awaits Eve-owned cleanup and release.
Browserbase state	Session can remain RUNNING.	Release is requested and verified through the shared helper.
Persisted session ID	Remains eligible for reconnect.	Cleared only after successful release.
Failed release	Can be masked by a successful tool result.	Surfaced and retained as suspect ownership.
Next call	Reuses the same facade/browser.	Creates fresh resources.
Browser close + release success	Local failure can be hidden.	Local cleanup failure is still surfaced.

end-to-end evidence

An exact-base live A/B probe navigated to example.com, called await browser.close(), then requested facade tools again:

Lifecycle result	Current main	Stack through this PR
Close call returned	Yes	Yes
Next call reused the same facade	Yes	No
Remote session after close	RUNNING	COMPLETED

The follow-up call on the changed implementation created a fresh session and closed it; both changed-side sessions reached COMPLETED. The intentionally leaked base session was released after recording the result.

The same eight public Online-Mind2Web-style prompts were run through the official Eve example on real Browserbase sessions. Each required navigation, multiple facade calls, snapshot/screenshot evidence, exact final title/URL, and browser close:

Result	Before	After
Manually correct task outcome	8/8	8/8
LLM-judge pass	7/8	7/8
All seven strict harness gates	2/8	5/8
Operationally clean trace	2/8	6/8
Browserbase cleanup	0/8 sessions	9/9 sessions

Nine sessions were created after the change because one unhealthy resource was replaced; all nine reached COMPLETED. The unchanged judge miss was a canonical-hostname false negative. Remaining strict failures were snapshot transport churn and facade/navigation limitations, not lifecycle failures.

test plan

• Eve tests: 9/9
• Eve typecheck
• Eve consumer eve build
• Core tests on the base PR: 37/37
• Focused oxfmt/oxlint

No changeset is included because the Eve integration is a private example.

---

Summary by cubic

Eve now closes and releases its facade-owned Browserbase session when model code calls await browser.close(), preventing reuse of a closed session and surfacing cleanup failures instead of hiding them. Before, close returned while Eve kept the session; now we await local cleanup, release via the shared helper, and create fresh resources on the next call.

• Adds a close hook on StagehandFacadeTools so explicit close triggers Eve-side cleanup and calls releaseBrowserbaseSession from @browserbasehq/stagehand-integrations/facade (replacing the prior best-effort REST call).
• Persists session metadata (apiKey, baseUrl, id) on the facade; clears the stored ID only after a successful release; a failed release marks the session suspect and throws BrowserbaseSessionReleaseError.
• Serializes cleanup with creation; reconnection skips a suspect session and launches fresh, and the next call after an explicit close creates new resources.
• Aggregates cleanup errors on explicit close: throws the single failure or an AggregateError when multiple occur; a browser-close failure still surfaces even if remote release succeeds.
• On Stagehand initialization failure after launch, attempts release and clears persisted ownership; marks the session suspect if release fails.
• Tests cover explicit close → fresh creation, failed release surfacing, browser-close failure with successful release, and init-failure cleanup.

^{Written for commit 96be869. Summary will update on new commits.}

[changeset-bot]

⚠️ No Changeset found

Latest commit: 96be869

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[cubic-dev-ai]

All reported issues were addressed across 2 files

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