feat(front) : retouches UX saisie bovin (filtre, toast, partial save, fix isSaisi)

- isSaisi : != null couvre les champs absents du JSON (API Platform strip null)
- UiNumberInput : ne réécrit target.value que si réellement clampé (fix saisie décimaux)
- Form : champs optionnels, payload partiel, toast de confirmation
- Page : filtre N° national au-dessus de la liste

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

frontend/components/entry-exit/bovine-info-form.vue

@@ -1,32 +1,32 @@
 <template>
-    <form class="space-y-6" :class="{ submitted }" @submit.prevent="submit">
-        <div class="grid grid-cols-2 gap-x-12 gap-y-6">
+    <form class="space-y-6" @submit.prevent="submit">
+        <div class="grid grid-cols-4 gap-x-12 gap-y-6">
             <UiNumberInput
                 v-model="form.receivedWeight"
                 label="Poids d'arrivée (kg)"
+                wrapperClass="flex-col"
+                labelClass="font-bold uppercase text-xl text-primary-700"
                 :min="0"
                 :step="1"
-                required
             />
             <UiNumberInput
                 v-model="form.pricePerKg"
-                label="Prix d'achat (kg)"
+                label="Prix au kg"
+                wrapperClass="flex-col"
+                labelClass="font-bold uppercase text-xl text-primary-700"
                 :min="0"
                 :step="0.01"
-                required
             />
             <UiSelect
                 v-model="form.buildingId"
                 label="Bâtiment"
                 :options="buildingOptions"
-                required
             />
             <UiSelect
                 v-model="form.buildingCaseId"
                 label="Case"
                 :options="caseOptions"
                 :disabled="form.buildingId === null"
-                required
             />
         </div>
 
@@ -66,15 +66,14 @@ interface FormState {
 }
 
 const form = reactive<FormState>({
-    receivedWeight: props.bovine.receivedWeight,
-    pricePerKg: props.bovine.pricePerKg,
+    receivedWeight: props.bovine.receivedWeight ?? null,
+    pricePerKg: props.bovine.pricePerKg ?? null,
     buildingId: props.bovine.buildingCase?.building?.id
         ?? props.bovine.effectiveBuilding?.id
         ?? null,
     buildingCaseId: props.bovine.buildingCase?.id ?? null
 })
 
-const submitted = ref(false)
 const isSaving = ref(false)
 
 const buildingOptions = computed(() =>
@@ -101,13 +100,15 @@ watch(() => form.buildingId, (newId) => {
 })
 
 const submit = async () => {
-    submitted.value = true
-    if (
-        form.receivedWeight === null
-        || form.pricePerKg === null
-        || form.buildingId === null
-        || form.buildingCaseId === null
-    ) {
+    const payload: Record<string, unknown> = {}
+    if (form.receivedWeight != null) payload.receivedWeight = form.receivedWeight
+    if (form.pricePerKg != null) payload.pricePerKg = form.pricePerKg
+    if (form.buildingCaseId != null) {
+        payload.buildingCase = `/api/building_cases/${form.buildingCaseId}`
+    }
+
+    if (Object.keys(payload).length === 0) {
+        emit('saved', props.bovine)
         return
     }
 
@@ -115,11 +116,8 @@ const submit = async () => {
     try {
         const updated = await api.patch<BovineData>(
             `bovines/${props.bovine.id}`,
-            {
-                receivedWeight: form.receivedWeight,
-                pricePerKg: form.pricePerKg,
-                buildingCase: `/api/building_cases/${form.buildingCaseId}`
-            }
+            payload,
+            { toastSuccessMessage: `Bovin ${props.bovine.nationalNumber} enregistré.` }
         )
         emit('saved', updated)
     } finally {