Address PR review feedback for OIDC login

- Remove sensitive nonce values from error messages to prevent logging leaks
- Guard ticker intervals against non-positive durations in SAML domain
  verifier and garbage collector to prevent panics
- Require both client ID and client secret for Google/Microsoft OIDC
  providers to be marked as enabled
- Replace http.DefaultClient with kit/httpclient for JWKS fetching to
  ensure proper timeouts
- Fix eslint indentation in SignInPage OIDC button click handler

Signed-off-by: Bryan Frimin <bryan@getprobo.com>

pkg/iam/saml/gc.go

@@ -71,6 +71,10 @@ func (gc *GarbageCollector) Run(ctx context.Context) error {
 		gc.logger.ErrorCtx(ctx, "cannot run initial cleanup", log.Error(err))
 	}
 
+	if gc.interval <= 0 {
+		return fmt.Errorf("cannot run SAML garbage collector: interval must be greater than zero")
+	}
+
 	ticker := time.NewTicker(gc.interval)
 	defer ticker.Stop()