Update Stagehand Sample App to be compatible with Stagehand v3

[dprevoznik]

Updated Stagehand example app to v3 Stagehand compatible version of script.

Implementation Checklist

• Implemented this change in TypeScript
• Implemented this change in Python

Testing

• All tests pass locally
• Linted
• Added tests for new functionality (if applicable)

---

Note

Upgrades the Stagehand TypeScript sample to v3 with a new teamsize-task, updates CLI invoke/deploy text, and bumps related dependencies.

• Templates — TypeScript stagehand
  • Migrate implementation to Stagehand v3 API in templates/typescript/stagehand/index.ts:
    • New teamsize-task that navigates YC Companies, searches by company, and extracts { teamSize } via zod schema.
    • Uses Stagehand v3 options (model, apiKey, domSettleTimeout) and stagehand.context.pages()[0].
    • Adds Kernel browser session handling (live view logging and explicit session deletion).
  • Rewrite README.md to describe the new task, I/O schema, setup, deploy, and invoke commands.
• CLI
  • Update template description to "Stagehand v3 SDK" and change invoke sample for ts-stagehand to teamsize-task in index.ts.
• Dependencies
  • Bump @browserbasehq/stagehand to ^3.0.1, @onkernel/sdk to ^0.18.0, and pin zod to 3.25.67 (lockfile updated accordingly).

^{Written by Cursor Bugbot for commit a8b5265. This will update automatically on new commits. Configure here.}

[mesa-dot-dev]

Mesa Description

Updated Stagehand example app to v3 Stagehand compatible version of script.

Implementation Checklist

• Implemented this change in TypeScript
• Implemented this change in Python

Testing

• All tests pass locally
• Linted
• Added tests for new functionality (if applicable)

---

Note

This PR updates the TypeScript Stagehand sample application to be compatible with Stagehand v3, introducing a more practical example task and updating relevant dependencies.

• Stagehand TS Sample App (templates/typescript/stagehand):
  • Migrated the core logic to the Stagehand v3 API.
  • Replaced the generic stagehand-task with a new headcount-task that demonstrates a real-world browser automation flow: searching for a company on Y Combinator and extracting its team size.
  • Updated the README.md to reflect the new functionality, setup instructions, and invocation examples.
• CLI (index.ts):
  • Updated the template description in the main CLI to specify "Stagehand v3 SDK" for clarity.
• Dependencies:
  • Bumped @browserbasehq/stagehand to ^3.0.1 and @onkernel/sdk to ^0.18.0 in package.json to support the v3 API.

^{Description generated by Mesa. Update settings}

[masnwilliams]

lgtm