[feat] Add BrowserUseTools for Browser Use Cloud browser tasks

[gregpr07]

Summary

Adds BrowserUseTools (libs/agno/agno/tools/browser_use.py). One tool, run_browser_task(task, session_id=None), sync and async. It runs the task on the Browser Use Cloud agent (API v4, official browser-use-sdk), waits, and returns {"result", "session_id", "run_id"} as JSON. Passing session_id back continues in the same browser. Errors come back as {"error": ...} JSON.

• timeout (default 900 s) is forwarded to Toolkit; a run that exceeds it is cancelled so it stops using credits
• Optional extra browser-use = ["browser-use-sdk>=3.10.0"], added to agno[tools]; mypy override for browser_use_sdk.* (the SDK ships no py.typed)
• Cookbook cookbook/91_tools/browser_use_tools.py, README section, TEST_LOG entry

Why: BrowserbaseTools exposes low-level page actions. This hands a whole multi-step task (click, fill forms, log in, extract) to a hosted browser agent.

Fixes #11093

Type of change

• Bug fix
• New feature
• Breaking change
• Improvement
• Model update
• Other:

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Checklist

• Code complies with style guidelines
• Ran format/validation scripts (./scripts/format.sh and ./scripts/validate.sh)
• Self-review completed
• Documentation updated (comments, docstrings)
• Examples and guides: Relevant cookbook examples have been included or updated (if applicable)
• Tested in clean environment
• Tests added/updated (if applicable)

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Additional Notes

Proof:

• pytest libs/agno/tests/unit/tools/test_browser_use.py -> 9 passed on browser-use-sdk 3.10.0 and on 3.11.3. Tests run the real SDK against a fake API v4 over httpx.MockTransport: request body, follow-up session, failed run, API error, missing key sends no request, timeout cancels the run (sync and async), tool registration.
• A mutation check (drop the cancel call, drop session_id) fails 3 tests.
• ./scripts/validate.sh: ruff clean for agno, agnoctl and cookbook; cookbook pattern check clean; mypy reports 7 errors, all in untouched files under agno/db/ and agno/os/ and identical on main with the same local mypy, none in the new module. ruff format run on the changed files only.
• uv pip compile --extra tests before/after: the only change is browser-use-sdk==3.10.0 (no other version moves).
• Not run: a live call against Browser Use Cloud, which needs a funded key.

Risk: additive (new module, optional extra). Rollback: revert the commit.

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