fix: Migrate old lead notes as per the new format

erpnext/patches/v14_0/migrate_existing_lead_notes_as_per_the_new_format.py

@@ -0,0 +1,21 @@
+import frappe
+from frappe.utils import cstr, strip_html
+
+
+def execute():
+	for doctype in ("Lead", "Prospect"):
+		if not frappe.db.has_column(doctype, "notes"):
+			continue
+
+		dt = frappe.qb.DocType(doctype)
+		records = (
+			frappe.qb.from_(dt)
+			.select(dt.name, dt.notes, dt.modified_by, dt.modified)
+			.where(dt.notes.isnotnull() & dt.notes != "")
+		).run()
+
+		for d in records:
+			if strip_html(cstr(d.notes)).strip():
+				doc = frappe.get_doc(doctype, d.name)
+				doc.append("notes", {"note": d.notes, "added_by": d.modified_by, "added_on": d.modified})
+				doc.save()