* fix(cli): remap child session references on fork to prevent subagent state leaks
When forking a session, task tool parts referencing child sessions were
copied verbatim, causing both original and forked sessions to share the
same subagent references. This led to SSE events and permission prompts
leaking across sessions in the Agent Manager.
* fix: remove redundant recursive remapChildren call
Session.fork() already calls remapChildren via the hook, so the explicit
recursive call inside remapChildren was double-forking nested descendants.
Marius
c584eec1db