build: prepare clean AgentSeek API 0.3.0 artifacts

[webup]

Summary

• exclude local .superpowers work products from Hatch release archives
• add a release-packaging regression that locks the exclusion
• retain the merged Train B 0.3.0 version, runtime, lockfile, changelog, and documentation surfaces unchanged

No .superpowers or docs/superpowers file is part of this commit.

Release candidate

• wheel: agentseek_api-0.3.0-py3-none-any.whl
  • SHA-256: 2c1fd98a3910e15409495d207939a44e0638e40a0ea161ef43eefae4ac915633
• sdist: agentseek_api-0.3.0.tar.gz
  • SHA-256: 2bc523f0c45b4cf91c014206a218bc4ec2d80ad05d79d09f6d440e636d00a0dd
• Twine validates both artifacts
• both archives contain zero .superpowers paths
• isolated Python 3.12 wheel install imports from external site-packages and reports agentseek-api 0.3.0

Test plan

• packaging regression captured RED, then GREEN
• non-Docker unit + integration coverage: 1466 passed, 10 skipped, 14 deselected, coverage 90.20%
• release version consistency: 3 passed
• uv lock --check --offline
• Ruff check/format and git diff --check
• clean Python 3.12 build and Twine validation
• Train B exact-head hosted CI: https://github.com/ob-labs/agentseek-api/actions/runs/32400539402 (18/18 successful, including both Compose legs and Windows)

Target branch

• release/0.3.0 starts from and targets develop

[webup]

Thanks everyone—AgentSeek API v0.3.0 is now squash-merged and published from 1e1f980bf73209733974d274e7eaf80a50418257. The release workflow passed, GitHub Release and PyPI expose byte-identical verified artifacts, and neither public archive contains Superpowers work products.