Review follow-ups on the bash owner-token PR:
- packages/acp/README.md still described task isolation in object-identity terms
("records each background task's owning agent", "a different agent"). Rewrite
to the session-token model: ownership is by `session.header.id`, stored on the
executor's task, so a different Agent object on the same session may access it
and ownership survives a tool-bash HMR reload.
- The reviewer flagged that the notice routes by `session.header.id` while the
registry only enforces unique `agent.id`, so a programmatic caller could
register two agents sharing a session token and mis-route a notice (not
reachable via ACP). Rather than bolt a session-id invariant onto the generic
registry, add a proposed RFC (2026-06-20-unify-agent-and-session-id) to remove
the precondition by construction — an agent IS its session, one id — with a
full risks discussion (forecloses multi-session-actor / fork futures, makes the
config resume-or-create policy load-bearing, migration churn). The actual
unification ships as its own Codex-converged PR. Cross-linked from the
agent-lifecycle RFC's seam-precondition note.
- Reframe the tool-bash module-doc ownership paragraph to current-state (per the
new AGENTS.md doc convention): contrast storing the token on the executor vs
in the plugin as a standing rationale, not as "closing the old gap".
90a19f072d