Apply mechanical lint fixes for golangci-lint v2.12.2 rollout

Auto-remediate style-only findings (wsl_v5, nlreturn, noinlineerr,
modernize, intrange, perfsprint, usetesting, unconvert, errorlint,
gocritic, testifylint) and rename printf-style helpers to f-suffixed
names (goprintffuncname): ui.Writer message methods, cli.ReportErrorf,
database.Fatalf, vaultik stdoutf.

internal/s3/client_test.go

@@ -12,7 +12,8 @@ import (
 func TestClient(t *testing.T) {
 	ts := NewTestServer(t)
 	defer func() {
-		if err := ts.Cleanup(); err != nil {
+		err := ts.Cleanup()
+		if err != nil {
 			t.Errorf("cleanup failed: %v", err)
 		}
 	}()
@@ -35,6 +36,7 @@ func TestClient(t *testing.T) {
 	// Test PutObject
 	testKey := "foo/bar.txt"
 	testData := []byte("test data")
+
 	err = client.PutObject(ctx, testKey, bytes.NewReader(testData))
 	if err != nil {
 		t.Fatalf("failed to put object: %v", err)
@@ -46,7 +48,8 @@ func TestClient(t *testing.T) {
 		t.Fatalf("failed to get object: %v", err)
 	}
 	defer func() {
-		if err := reader.Close(); err != nil {
+		err := reader.Close()
+		if err != nil {
 			t.Errorf("failed to close reader: %v", err)
 		}
 	}()
@@ -65,6 +68,7 @@ func TestClient(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to head object: %v", err)
 	}
+
 	if !exists {
 		t.Error("expected object to exist")
 	}
@@ -74,9 +78,11 @@ func TestClient(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to list objects: %v", err)
 	}
+
 	if len(keys) != 1 {
 		t.Errorf("expected 1 key, got %d", len(keys))
 	}
+
 	if keys[0] != testKey {
 		t.Errorf("unexpected key: got %s, want %s", keys[0], testKey)
 	}
@@ -92,6 +98,7 @@ func TestClient(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to head object after deletion: %v", err)
 	}
+
 	if exists {
 		t.Error("expected object to not exist after deletion")
 	}