fix(scheduler): default require_plate_clear to False to match schema/UI (#1865)

check_queue() read the plate-clear setting with _get_bool_setting(default=True),
but SettingsSchema.require_plate_clear defaults False and the whole frontend
treats a missing value as off. Since _get_bool_setting returns its default when
no DB row exists, installs that never saved the setting enforced the plate-clear
gate the UI showed as disabled — FINISH-state printers never dispatched and no UI
control existed to clear awaiting_plate_clear. Read the setting with default=False
so the enforced behavior matches the schema and the toggle. Both defaults shipped
together in #752; this aligns them.

backend/app/services/print_scheduler.py

@@ -234,8 +234,14 @@ class PrintScheduler:
                 )
             items = list(result.scalars().all())
 
-            # Read plate-clear setting once per queue check
-            require_plate_clear = await self._get_bool_setting(db, "require_plate_clear", default=True)
+            # Read plate-clear setting once per queue check. Default MUST be
+            # False to match the schema (SettingsSchema.require_plate_clear
+            # defaults False) and the frontend (toggle + card badge both treat a
+            # missing value as off). When no settings row exists, a True default
+            # here re-enabled the plate-clear gate the UI showed as disabled,
+            # blocking dispatch to FINISH-state printers forever with no UI path
+            # to clear it (#1865).
+            require_plate_clear = await self._get_bool_setting(db, "require_plate_clear", default=False)
 
             if not items:
                 # No pending items — still check auto-drying on idle printers