feat: correct total tax on incoming invoices

backend/db/migrations/0062_incoming_invoice_tax_override.sql

@@ -0,0 +1 @@
+ALTER TABLE "incominginvoices" ADD COLUMN "tax_amount_override" numeric(12, 2);

backend/db/migrations/meta/_journal.json

@@ -414,6 +414,13 @@
       "when": 1786280400000,
       "tag": "0061_additional_skr03_accounts",
       "breakpoints": true
+    },
+    {
+      "idx": 59,
+      "version": "7",
+      "when": 1786284000000,
+      "tag": "0062_incoming_invoice_tax_override",
+      "breakpoints": true
     }
   ]
 }