fix(plan history): use RUN_EVERY, not PREDICT_STEP, for the one-run wait

history_slot() and history_refresh_minutes() wait one run past a slot boundary, and their docstrings
call that run PREDICT_STEP. One run is RUN_EVERY in const.py; PREDICT_STEP is the prediction step. Both
are 5 today, so nothing changes now, but if either changed the wait would quietly be wrong.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: chalfontchubby

apps/predbat/output.py

@@ -21,7 +21,7 @@
 from html import escape as escape_html
 from datetime import timedelta
 from predbat import THIS_VERSION_DISPLAY
-from const import TIME_FORMAT, PREDICT_STEP, EXPORT_LIMIT_IDLE, MINUTE_WATT, FULL_EXPORT_POWER, EXPORT_MODE_TARGET, EXPORT_MODE_FREEZE, EXPORT_MODE_IDLE, CHARGE_STATE_PRECEDENCE, EXPORT_STATE_PRECEDENCE
+from const import TIME_FORMAT, PREDICT_STEP, RUN_EVERY, EXPORT_LIMIT_IDLE, MINUTE_WATT, FULL_EXPORT_POWER, EXPORT_MODE_TARGET, EXPORT_MODE_FREEZE, EXPORT_MODE_IDLE, CHARGE_STATE_PRECEDENCE, EXPORT_STATE_PRECEDENCE
 from utils import dp0, dp1, dp2, dp3, calc_percent_limit, minute_data, minute_data_state, find_charge_rate, export_mode_of, export_target_of, export_power_of, export_limit_sort_key, pack_export_limit, export_limit_from_stored
 from prediction import Prediction
 
@@ -3189,18 +3189,18 @@ def plan_row_holding_for_car(self, minute_start, minute_end, car_hold_minutes=No
     def history_slot(self, when):
         """Which plan slot the plan history rebuild at when counts towards, as (date, slot number from midnight).
 
-        Slots are plan_interval_minutes long, shifted one run (PREDICT_STEP) later: the run at a slot boundary
+        Slots are plan_interval_minutes long, shifted one run (RUN_EVERY) later: the run at a slot boundary
         writes predbat.cost_today seconds before calculate_yesterday() reads its history back from Home
         Assistant, so the slot just finished is rebuilt on the next run, once that value is recorded. This only
         helps when that next run re-plans; with calculate_plan_every at or above the slot length, re-plans can
         fall on boundaries and the rebuild then happens there.
         """
-        when = when - timedelta(minutes=PREDICT_STEP)
+        when = when - timedelta(minutes=RUN_EVERY)
         return when.date(), (when.hour * 60 + when.minute) // self.plan_interval_minutes
 
     def history_refresh_minutes(self):
         """The longest the plan history should go between rebuilds: a slot, the run it waits, and up to one re-plan interval."""
-        return self.plan_interval_minutes + PREDICT_STEP + self.calculate_plan_every
+        return self.plan_interval_minutes + RUN_EVERY + self.calculate_plan_every
 
     def calculate_yesterday(self):
         """