In-chat cronjob tool reached cron.jobs whose path constants snapshot at import, so a
chat under a named profile hit the DEFAULT profile's cron dirs. Adds a per-turn
contextvar (_STREAMING_CRON_PROFILE_HOME, reset on every exit) + a tool-call-boundary
wrapper that enters cron_profile_context_for_home() only while the cronjob handler runs
(cron lock, restored immediately — no whole-turn global mutation). Verified: agent
executor's propagate_context_to_thread uses unfiltered contextvars.copy_context() so the
contextvar reaches the sync handler on the ThreadPool worker; reset-token symmetry intact.
Code byte-faithful from PR head c3fd6ab22f8c. 12 own tests pass.
Co-authored-by: nesquena-hermes <agent@nesquena-hermes>
Co-authored-by: roian6 <roian6@users.noreply.github.com>
