Prevent tenant merge dry-run memory spikes

backend/src/utils/tenantMergePlan.ts

@@ -53,9 +53,13 @@ const comparableRow = (row: Record<string, any>) => Object.fromEntries(
         .sort(([left], [right]) => left.localeCompare(right))
 )
 
-const rowDifferences = (source: Record<string, any>, target: Record<string, any>) => {
+const rowDifferences = (table: string, source: Record<string, any>, target: Record<string, any>) => {
     const sourceComparable = comparableRow(source)
     const targetComparable = comparableRow(target)
+    if (table === "citys") {
+        delete sourceComparable.geometry
+        delete targetComparable.geometry
+    }
     const columns = Array.from(new Set([
         ...Object.keys(sourceComparable),
         ...Object.keys(targetComparable),
@@ -111,7 +115,7 @@ export const buildTenantMergePlan = (
             const naturalTarget = sourceNaturalKey ? targetByNaturalKey.get(sourceNaturalKey) : undefined
             const primaryTarget = targetByPrimaryKey.get(sourceKey)
             const targetRow = naturalTarget || primaryTarget || null
-            const differences = targetRow ? rowDifferences(sourceRow, targetRow) : []
+            const differences = targetRow ? rowDifferences(table, sourceRow, targetRow) : []
             let kind: TenantMergeKind
 
             if (!targetRow) {

backend/src/utils/tenantMergeService.ts

@@ -161,16 +161,43 @@ const sensitiveColumns = new Set([
     "tokenHash",
 ])
 
-const redactRow = (row: Record<string, any> | null) => row && Object.fromEntries(
-    Object.entries(row).map(([column, value]) => [column, sensitiveColumns.has(column) && value ? "***" : value])
-)
+const compactValue = (value: any) => {
+    if (value === null || typeof value !== "object") return value
+    const serialized = JSON.stringify(value)
+    return `[Struktur mit ${serialized.length} Zeichen]`
+}
+
+const compactReviewRow = (row: Record<string, any> | null, differences: string[]) => {
+    if (!row) return null
+    const displayColumns = new Set([
+        "id",
+        "tenant",
+        "tenant_id",
+        "name",
+        "label",
+        "title",
+        "number",
+        "email",
+        "zip",
+        "short",
+        "accountChart",
+        ...differences,
+    ])
+
+    return Object.fromEntries(Object.entries(row)
+        .filter(([column]) => displayColumns.has(column))
+        .map(([column, value]) => [
+            column,
+            sensitiveColumns.has(column) && value ? "***" : compactValue(value),
+        ]))
+}
 
 export const sanitizeTenantMergePlan = (plan: TenantMergePlan): TenantMergePlan => ({
     ...plan,
-    items: plan.items.map((item) => ({
+    items: plan.items.filter((item) => item.kind !== "existing").map((item) => ({
         ...item,
-        sourceRow: redactRow(item.sourceRow) || {},
-        targetRow: redactRow(item.targetRow),
+        sourceRow: compactReviewRow(item.sourceRow, item.differences) || {},
+        targetRow: compactReviewRow(item.targetRow, item.differences),
     })),
 })