Python runtime slice #

Read ../../docs/runtime-v2/STATUS.md and ../../docs/runtime-v2/HANDOFF.md first. Use python tools/check_runtime.py from the repository root. No pip install is needed. The tests/peer.py host is a test double; do not mistake it for the Rust runtime.

Keep the workbench namespace separate from required hook execution. No protocol over stdout. Keep correlation IDs, generation checks, output bounds and expired background-effect scopes. Terminal wait is a host-owned yield, not a Python sleep. All durable state lives in the host; there is no pickle/heap-restoration contract. Published hooks are source entrypoints, not closures capturing cell globals. New imports remain ordinary Python vocabulary, not one Rust tool registration per helper. Local receipts are not remote delivery semantics.