Remove the legacy stack the hexagonal slice replaced, now that nothing
assembles it: app/scheduler/service.py (the old orchestration),
app/gateway/routers/scheduled_tasks.py (the old dict-returning router,
no longer mounted), the deerflow/scheduler package (its cron/timezone
rules live in ScheduleSpec), the dict-returning repositories in
persistence/scheduled_task*/sql.py, and the deps.py providers and
app.state wiring that served them. The ORM rows and the
uq_scheduled_task_run_active partial unique index stay -- the table
definitions live with the shared engine/alembic infrastructure and the
schedule adapters are their only readers and writers.
The legacy test suites go with the code they pinned; every scenario has
a counterpart in the new suites. The one suite that guarded semantics
rather than the old implementation -- the real-database dispatch-race
TOCTOU tests -- is migrated to the new stack as
test_schedule_dispatch_race.py, driving ScheduleService over the real
SQL adapters with the same barrier, natural-timing, and index-semantics
cases.
Docs and comments that named the old classes as the current wiring
(backend/AGENTS.md, reload_boundary.py, channel/service comments) now
name the composition-root wiring instead.
Queue comments received while a run is active, then submit one deduplicated follow-up after it finishes. Failed drains are requeued and watcher tasks stop cleanly with the channel manager.
