fix(web-admin): persist cleared vehicle/personnel photoUrls on save

Co-authored-by: Cursor <cursoragent@cursor.com>

web-admin/src/views/pl/personnel/index.vue

@@ -844,7 +844,7 @@ async function handleSubmit() {
       personnelAffiliation: formData.personnelAffiliation,
       status: formData.status,
       remark: formData.remark || undefined,
-      photoUrls: formData.photoUrls || undefined,
+      photoUrls: formData.photoUrls ?? '',
       certList: certList.value.map(c => ({
         certId: c.certId,
         certName: c.certName.trim(),

web-admin/src/views/pl/self-vehicle/index.vue

@@ -1003,7 +1003,7 @@ async function handleSubmit() {
       loadCapacity: formData.loadCapacity,
       vehicleStatus: formData.vehicleStatus,
       remark: formData.remark,
-      photoUrls: formData.photoUrls || undefined,
+      photoUrls: formData.photoUrls ?? '',
       personnelList: personnelList.value.map(p => ({
         personnelId: p.personnelId,
         personnelName: p.personnelName.trim(),

web-admin/src/views/pl/vehicle/index.vue

@@ -1048,7 +1048,7 @@ async function handleSubmit() {
       loadCapacity: formData.loadCapacity,
       vehicleStatus: formData.vehicleStatus,
       remark: formData.remark,
-      photoUrls: formData.photoUrls || undefined,
+      photoUrls: formData.photoUrls ?? '',
       personnelList: personnelList.value.map(p => ({
         personnelId: p.personnelId,
         personnelName: p.personnelName.trim(),