sched: extract typed preparer/dispatcher seams; test impl out of production (F6)

tests/scheduling/test_recovery.py

@@ -6,10 +6,17 @@ from datetime import UTC, datetime
 from pathlib import Path
 from typing import Any
 
+from tests.scheduling.controlled import (
+    DictDeployments,
+    ScriptedDispatcher,
+    fixture_environment,
+)
 from wf_artifacts.runs.store import FileRunStore
 from wf_scheduling import recovery as sched_recovery
+from wf_scheduling.calendar import OneShotSource
 from wf_scheduling.models import Schedule
 from wf_scheduling.poll import Scheduler
+from wf_scheduling.prepare import SchedulePreparer
 from wf_scheduling.store import FileScheduleStore
 
 
@@ -92,7 +99,6 @@ def test_recovery_never_executes_pending_until_poll(tmp_path: Path) -> None:
 
     from tests.artifacts.test_run_store import artifact as _artifact
     from tests.artifacts.test_run_store import deployment as _deployment
-    from tests.scheduling.test_poll import OneShotSource
     from wf_api.run_lifecycle import persist_admission
     from wf_artifacts import PinnedRunEnvironment
 
@@ -124,7 +130,11 @@ def test_recovery_never_executes_pending_until_poll(tmp_path: Path) -> None:
         run_store=run_store,
         sources=sources,  # type: ignore[arg-type]
         capacity=4,
-        outcomes={"*": "complete"},
+        preparer=SchedulePreparer(
+            DictDeployments({"dep-1": {"rev": 1, "required": []}}),
+            fixture_environment,
+        ),
+        dispatcher=ScriptedDispatcher({"*": "complete"}),
     )
     sched_store.save_consumed("a", ts(2026, 9, 8, 12, 0))
     sched.poll(ts(2026, 9, 8, 12, 1))