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/chunker/chunker_isolated_test.go

@@ -42,7 +42,7 @@ func TestChunkerExpectedChunkCount(t *testing.T) {
 
 			// Create data with some variation to trigger chunk boundaries
 			data := make([]byte, tt.fileSize)
-			for i := 0; i < len(data); i++ {
+			for i := range data {
 				// Use a pattern that should create boundaries
 				data[i] = byte((i * 17) ^ (i >> 5))
 			}
@@ -59,6 +59,7 @@ func TestChunkerExpectedChunkCount(t *testing.T) {
 				t.Errorf("too few chunks: got %d, expected at least %d",
 					len(chunks), tt.minExpected)
 			}
+
 			if len(chunks) > tt.maxExpected {
 				t.Errorf("too many chunks: got %d, expected at most %d",
 					len(chunks), tt.maxExpected)
@@ -69,6 +70,7 @@ func TestChunkerExpectedChunkCount(t *testing.T) {
 			for _, chunk := range chunks {
 				reconstructed = append(reconstructed, chunk.Data...)
 			}
+
 			if !bytes.Equal(data, reconstructed) {
 				t.Error("reconstructed data doesn't match original")
 			}