v0.5.0

Add separate chat and task tool approval policies to synchronous and asynchronous Agent APIs, including structured builtin/MCP references and version restoration. Session approvals expose tool identity and optional message/timestamp metadata through the existing list/decide/join lifecycle.

Includes typed inputs and public response models, examples, and strict separation of policy modes (full/deny/manual/auto) from persisted decisions (pending/approved/denied).

Validation: 175 installed-wheel tests, mypy/pyright, Ruff, and Python 3.11–3.14 compatibility checks. Backend policy runtime suite: 19 tests passed at 427a4672.

See PR #16 and CHANGELOG.md.