feat(integrations): add Taskmarket requester toolset

[a1271981054]

Fixes #6717

Summary

This PR adds a self-contained google.adk.integrations.taskmarket package for
Taskmarket requester workflows:

• list_tasks, get_task, and list_submissions read live public API data.
• preview_task produces an exact review record with description, reward,
  duration, deadline, mode, tags, Base chain ID, USDC contract, and a
  conservative maximum spend.
• create_task is wrapped with ADK's confirmation gate and additionally
  requires confirm=True plus the unchanged preview token.
• Before the first-party CLI write it verifies Base/USDC configuration and
  available balance. It invokes taskmarket task create once, without shell
  interpolation or automatic retries.
• A failed or timed-out write is surfaced as failed/unknown and instructs the
  caller to inspect live Taskmarket status before doing anything else.
• No private keys, seed phrases, tokens, cookies, or wallet credentials are
  accepted or stored by ADK.

Usage

Install and initialize the first-party CLI outside ADK:

npm install -g @lucid-agents/taskmarket
taskmarket init

Then add TaskMarketToolset() to an ADK agent. The integration documentation
in src/google/adk/integrations/taskmarket/README.md instructs the agent to
show the preview and obtain explicit user confirmation before creating a task,
and to keep submission acceptance/rejection human-reviewed.

Validation

Local validation on Python 3.12:

• pytest -q tests/unittests/integrations/taskmarket/test_taskmarket_toolset.py — 8 passed
• pytest -q tests/unittests/integrations — 582 passed, 2 skipped, 19 subtests passed
• pyink --check — passed
• isort --check-only — passed
• ruff check — passed
• mypy src/google/adk/integrations/taskmarket — passed
• scripts/compliance_checks.py — passed

The focused tests cover the exact preview token, explicit confirmation,
changed-request rejection, Base/USDC and balance preflight, no blind retry on
ambiguous writes, and public API reads.

Upstream and Taskmarket evidence

• Upstream repository: https://github.com/google/adk-python
• Issue: Add a safe Taskmarket requester toolset #6717
• Pull request: feat(integrations): add Taskmarket requester toolset #6718
• Exact commit: c22518c2ff7c23fa758c5b62cd2b46a3dc9f9fa2
• Current PR status: open, non-draft, review required; header and changes
  checks passed. The triage check is in progress. The Google CLA check asks a
  first-time contributor to sign the upstream CLA; no CLA was signed or
  represented on the user's behalf.
• Taskmarket task: 0xfb182f610d57a6c056a8cfd1c9b691a0869c1e0d67c041ac27ed9f42a9c732a1
• Taskmarket submission: 2a662c3d-e2f1-4a03-bc03-a1c8ab6ed4b1
• Submission transaction: 0xbc7cf3ce97cfcc627f5d65ed9a2c156cffafd8c85482d604c4d1291ac612acfe
• Deliverable hash: 0xff7d123aab5940c14c6cb63aec51fb4d9fef96a7d96a5418267b782a068db876
• Task status after submission: open/active, 18 submissions, 0 awards at
  evidence capture. Selection and payment remain pending.

The implementation is a small integration package and does not change ADK core
agent or tool execution semantics. It uses AI-assisted development; all
behavior is covered by the tests and validation commands above.

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[GWeale]

thanks for the pr. we dont take vendor-specific integrations into adk core, the framework would end up owning an integration per product and we cant maintain or test those against live third-party services.

this works fine as a standalone package. you can publish it and list it in the integrations catalog at adk.dev/integrations, which is where users look for this.

closing for that reason.