2.6.8: dependency sweep (anyio, ruff, ty) (#84)

## Summary

Dependency sweep, 2026-09-05, and the 2.6.8 version bump so
agentscore-commerce can move its floor in the same waterfall. The lock
moves anyio 4.15.0, ruff 0.16.6, ty 0.0.78; `uv lock` re-run after the
version bump so the lock's embedded project version matches. No
prerelease resolved.

Worked with Varun, who asked for the SDK-first sweep.

## Type of change

- [ ] Bug fix (no breaking change)
- [ ] New feature (no breaking change)
- [ ] Breaking change (existing callers must update)
- [x] Docs, tests, or internal maintenance only

## Public API

none

## Test plan

`uv sync --all-extras --all-groups`; `ruff check`, `ruff format
--check`, `ty check`, and vulture with CI's exact invocation all exit 0;
pytest 183 passed, 8 skipped, coverage 100%.

## Checklist

- [x] Tests cover the new behavior, and the suite passes locally
- [x] Lint, format, and type checks pass
- [x] Docs and README examples updated if the public surface changed
- [x] No secrets, credentials, or personal data in the diff or the tests

Author: vvillait88

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "agentscore-py"
-version = "2.6.7"
+version = "2.6.8"
 description = "Python client for the AgentScore APIs"
 readme = "README.md"
 license = "MIT"