fix(cli): omit undefined screenshot options

[shrey150]

Summary

• omit absent screenshot options instead of serializing explicit undefined values onto the V4 wire
• preserve screenshot syntax, timeout, file/base64 result shapes, and populated option behavior
• add regression coverage for default and fully populated screenshot requests

Refreshed on 2026-08-10 against the current parent and v4-spike commit d7556e9a.

E2E Test Matrix

Command / flow	Observed output	Confidence / sufficiency
2026-08-10 cumulative stack refresh on Chrome Stable 151	pnpm build passed 6/6 tasks; pnpm check passed 11/11 tasks with 0 errors; the full pnpm test graph exited 0, including 17/17 protocol browser tests and 15/15 local SDK browser tests	Proves the updated six-PR stack is compatible with v4-spike d7556e9a across build, static checks, unit tests, and real-browser suites.
Clean coordinated-release tarball consumer at the cumulative tip	Packed workspace Stagehand and Browse, installed both into an empty npm project, opened example.com, produced a snapshot, clicked through to IANA, filled an injected input, and read back published-v4-ok	Proves the intended co-published artifacts work outside the monorepo with a real Chrome session; it does not substitute for a credentialed Browserbase smoke.
corepack pnpm --dir packages/cli exec vitest run tests/driver-commands.test.ts	1 file passed; 24/24 tests passed	Covers minimal and populated V4 screenshot requests, cumulatively including the parent byte encoding.
corepack pnpm --filter browse test:unit	25 files passed; 380/380 tests passed	Covers the cumulative CLI contract on the refreshed V4 tip.
Real managed-local screenshot --base64	15,180 base64 characters decoded to 11,384 bytes with a valid PNG signature	Exercises the real browser, extension, V4 screenshot RPC, CLI JSON output, and cleanup.
Deterministic local CLI eval suite	18/18 tasks passed, including page-info/screenshot	Independent end-to-end screenshot proof through the workspace CLI eval adapter.
Final repository gates	6/6 build tasks; 11/11 checks; 400 warnings and 0 errors	Proves the screenshot layer builds and passes all repository gates.

Includes a browse patch changeset for the default screenshot fix.

Final release validation (2026-08-10)

At the cumulative stack tip:

• release validation now recognizes public browse changesets
• a Changesets version dry run resolves browse 0.9.7, Stagehand 4.0.1, extension 1.0.1, and Go 4.0.1
• the packed Browse 0.9.7 manifest rewrites workspace:* to exact Stagehand 4.0.1
• a clean npm consumer installed those versioned tarballs and completed real-Chrome open, snapshot, model-free click, URL read, and stop with zero audit vulnerabilities

[changeset-bot]

🦋 Changeset detected

Latest commit: 651e091

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
browse	Patch

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[shrey150]

Superseded by #2834. The screenshot adapter there omits undefined options when building the V4 screenshot request, so the compatibility fix is folded into the runtime migration where it is exercised by the CLI tests. Closing this draft.