Changes

Co-authored-by: renee-png <262607627+renee-png@users.noreply.github.com>

src/routes/settings.import.tsx

@@ -1206,17 +1206,49 @@ function ImportPage() {
         return data.id;
       };
 
+      // Pre-load existing invoices by number so we can defer client resolution
+      // when the invoice already exists with a real client_id (don't clobber
+      // it with a placeholder).
+      const invNumbers = mapped.map((r) => String(r.invoice_number ?? "")).filter(Boolean);
+      const existingInvClient = new Map<string, string>(); // invoice_number -> client_id
+      for (let k = 0; k < invNumbers.length; k += 500) {
+        const slice = invNumbers.slice(k, k + 500);
+        const { data } = await supabase
+          .from("invoices")
+          .select("invoice_number, client_id")
+          .in("invoice_number", slice);
+        for (const row of (data ?? []) as { invoice_number: string; client_id: string }[]) {
+          if (row.client_id) existingInvClient.set(row.invoice_number, row.client_id);
+        }
+      }
+
       const resolved: Row[] = [];
       for (const row of mapped) {
         let clientId: string | null = (row.client_id as string | null) ?? null;
         if (!clientId) {
           const cExt = row._clientext ? String(row._clientext).trim() : null;
           const cName = row._clientname ? String(row._clientname).trim() : null;
-          const nameGuess = cName || cExt || "Imported (no client)";
-          clientId = await ensureArchivedClient(nameGuess, cExt);
-          if (!clientId) { bumpSkip("auto-create client failed"); continue; }
+          // If this invoice already exists with a real client, inherit it
+          // instead of falling back to a placeholder — prevents wiping good
+          // client links during a re-import of the invoices CSV.
+          const invNum = row.invoice_number ? String(row.invoice_number) : "";
+          const existingClient = invNum ? existingInvClient.get(invNum) : null;
+          if (existingClient) {
+            clientId = existingClient;
+          } else if (cName || cExt) {
+            // Only auto-create a placeholder when the CSV actually had a
+            // client hint we couldn't resolve. Pure-blank rows are left
+            // unset so the merge step skips client_id entirely.
+            const nameGuess = cName || cExt!;
+            clientId = await ensureArchivedClient(nameGuess, cExt);
+            if (!clientId) { bumpSkip("auto-create client failed"); continue; }
+          } else {
+            // No client info at all — leave client_id unset. The merge step
+            // will skip it (preserving any existing value); inserts will
+            // route through the catch-all placeholder below.
+          }
         }
-        row.client_id = clientId;
+        if (clientId) row.client_id = clientId;
 
         // If the invoice mentions a case but we don't have it, create an
         // archived placeholder case so the reference is preserved.