fix: duplicate scorecard period when supplier is created on a month end

make_all_scorecards' dedup query used strict bounds, so a single-day
period (supplier created on a month's last day -> start == end under
"Per Month") never matched its own window and was re-created on every
call. The daily refresh_scorecards job would insert a duplicate
submitted period each day for such suppliers, and
test_make_all_scorecards_is_idempotent fails on any date where
nowdate() - 75 days lands on a month end — both nightly server suites
went red on 2026-07-14 (75 days after April 30).

Inclusive bounds cannot false-match adjacent periods: each next period
starts at end_date + 1, so closed intervals never touch.

erpnext/buying/doctype/supplier_scorecard/supplier_scorecard.py

@@ -201,14 +201,16 @@ def make_all_scorecards(docname: str):
 
 	while (start_date < todays) and (end_date <= todays):
 		# check to make sure there is no scorecard period already created
+		# (inclusive bounds: a single-day period — supplier created on a month's
+		# last day — must match its own window, else it is re-created every run)
 		scorecards = frappe.get_all(
 			"Supplier Scorecard Period",
 			fields=["name"],
 			filters={
 				"scorecard": docname,
 				"docstatus": 1,
-				"start_date": ["<", end_date],
-				"end_date": [">", start_date],
+				"start_date": ["<=", end_date],
+				"end_date": [">=", start_date],
 			},
 			order_by="end_date desc",
 		)