refactor(workspace): restore yaml exports and align docker builds

- return scenario export payloads as yaml to match existing workflows

- harden step reordering flow for drag-and-drop and one-based ui labels

- switch server container to workspace-lockfile installs and root ignore rules

client/src/pages/scenario/EditStepPage.tsx

@@ -13,11 +13,9 @@ export function EditStepPage() {
 
   const [scenario, setScenario] = useState<Scenario | null>(null);
   const [step, setStep] = useState<ScenarioStep | null>(null);
-  const [order, setOrder] = useState('');
   const [title, setTitle] = useState('');
   const [execCode, setExecCode] = useState('');
   const [validateCode, setValidateCode] = useState('');
-  const [orderError, setOrderError] = useState('');
   const [loading, setLoading] = useState(true);
   const [saving, setSaving] = useState(false);
   const [error, setError] = useState<string | null>(null);
@@ -28,7 +26,6 @@ export function EditStepPage() {
       .then(([sc, st]) => {
         setScenario(sc);
         setStep(st);
-        setOrder(String(st.order));
         setTitle(st.title ?? '');
         setExecCode(st.execCode ?? '');
         setValidateCode(st.validateCode ?? '');
@@ -37,23 +34,12 @@ export function EditStepPage() {
       .finally(() => setLoading(false));
   }, [id, stepId]);
 
-  const validate = (): boolean => {
-    let valid = true;
-    if (isNaN(Number(order)) || Number(order) < 0) {
-      setOrderError(t('steps.form_order_invalid'));
-      valid = false;
-    }
-    return valid;
-  };
-
   const handleSubmit = async (e: React.FormEvent) => {
     e.preventDefault();
-    if (!validate()) return;
     setSaving(true);
     setError(null);
     try {
       await steps.update(id!, stepId!, {
-        order: Number(order),
         title: title.trim() || undefined,
         execCode: execCode.trim() || undefined,
         validateCode: validateCode.trim() || undefined,
@@ -76,7 +62,7 @@ export function EditStepPage() {
               label: scenario?.name ?? `#${id}`,
               onClick: () => navigate(`/scenarios/${id}`),
             },
-            { label: t('steps.edit_title', { order: step?.order ?? stepId }) },
+            { label: t('steps.edit_title', { order: step ? step.order + 1 : stepId }) },
           ]}
         />
       </div>
@@ -88,17 +74,6 @@ export function EditStepPage() {
         <form onSubmit={handleSubmit} noValidate>
           <Card className={styles.formCardFull}>
             <div className={styles.formFields}>
-              <Input
-                label={t('steps.form_order')}
-                type="number"
-                min={0}
-                value={order}
-                onChange={(e) => {
-                  setOrder(e.target.value);
-                  setOrderError('');
-                }}
-                error={orderError || undefined}
-              />
               <Input
                 label={t('steps.form_title')}
                 placeholder={t('steps.form_title_placeholder')}