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/config/config_test.go

@@ -41,6 +41,7 @@ func TestConfigLoad(t *testing.T) {
 	if len(cfg.AgeRecipients) != 2 {
 		t.Errorf("Expected 2 age recipients, got %d", len(cfg.AgeRecipients))
 	}
+
 	if cfg.AgeRecipients[0] != TEST_SNEAK_AGE_PUBLIC_KEY {
 		t.Errorf("Expected first age recipient to be %s, got '%s'", TEST_SNEAK_AGE_PUBLIC_KEY, cfg.AgeRecipients[0])
 	}