Replaced the "transaction" property with the "url" property in the ReportEntry model of the income and expenses log, so that the report entry does not need to keep the transaction object.

src/accounting/report/reports/income_expenses.py

@@ -47,8 +47,6 @@ class ReportEntry:
 
         :param entry: The journal entry.
         """
-        self.transaction: Transaction | None = None
-        """The transaction."""
         self.is_brought_forward: bool = False
         """Whether this is the brought-forward entry."""
         self.is_total: bool = False
@@ -67,14 +65,17 @@ class ReportEntry:
         """The balance."""
         self.note: str | None = None
         """The note."""
+        self.url: str | None = None
+        """The URL to the journal entry."""
         if entry is not None:
-            self.transaction = entry.transaction
             self.date = entry.transaction.date
             self.account = entry.account
             self.summary = entry.summary
             self.income = None if entry.is_debit else entry.amount
             self.expense = entry.amount if entry.is_debit else None
             self.note = entry.transaction.note
+            self.url = url_for("accounting.transaction.detail",
+                               txn=entry.transaction)
 
 
 class EntryCollector: