fix(ui): localize SeaweedFS object storage labels and placeholders

The SeaweedFS endpoint field labels and placeholders were hard-coded in
English while the surrounding form uses $t(...) with locale keys, leaving
the new provider configuration untranslated for non-English users. Added
label.seaweedfs.s3.url, label.seaweedfs.iam.url,
label.seaweedfs.metrics.url and matching .placeholder entries to
en.json and bound the form fields through the localization mechanism.

Author: chrislusf

ui/public/locales/en.json

@@ -2381,6 +2381,12 @@
 "label.securitygroupenabled": "Security Groups enabled",
 "label.securitygroups": "Security groups",
 "label.securitygroupsenabled": "Security Groups enabled",
+"label.seaweedfs.s3.url": "S3 Endpoint URL (optional)",
+"label.seaweedfs.s3.url.placeholder": "Override S3 endpoint if different from URL",
+"label.seaweedfs.iam.url": "IAM Endpoint URL (optional)",
+"label.seaweedfs.iam.url.placeholder": "Override IAM endpoint if different from S3 URL",
+"label.seaweedfs.metrics.url": "Prometheus Metrics URL (optional)",
+"label.seaweedfs.metrics.url.placeholder": "SeaweedFS S3 server metrics port, e.g. http://seaweedfs-s3:9327",
 "label.select": "Select",
 "label.see.more.info.cpu.usage": "See more info about CPU usage",
 "label.see.more.info.memory.usage": "See more info about memory usage",

ui/src/views/infra/AddObjectStorage.vue

@@ -89,14 +89,14 @@
           <a-form-item name="secretKey" ref="secretKey" :label="$t('label.secret.key')">
             <a-input-password v-model:value="form.secretKey" autocomplete="off"/>
           </a-form-item>
-          <a-form-item name="s3Url" ref="s3Url" label="S3 Endpoint URL (optional)">
-            <a-input v-model:value="form.s3Url" placeholder="Override S3 endpoint if different from URL"/>
+          <a-form-item name="s3Url" ref="s3Url" :label="$t('label.seaweedfs.s3.url')">
+            <a-input v-model:value="form.s3Url" :placeholder="$t('label.seaweedfs.s3.url.placeholder')"/>
           </a-form-item>
-          <a-form-item name="iamUrl" ref="iamUrl" label="IAM Endpoint URL (optional)">
-            <a-input v-model:value="form.iamUrl" placeholder="Override IAM endpoint if different from S3 URL"/>
+          <a-form-item name="iamUrl" ref="iamUrl" :label="$t('label.seaweedfs.iam.url')">
+            <a-input v-model:value="form.iamUrl" :placeholder="$t('label.seaweedfs.iam.url.placeholder')"/>
           </a-form-item>
-          <a-form-item name="metricsUrl" ref="metricsUrl" label="Prometheus Metrics URL (optional)">
-            <a-input v-model:value="form.metricsUrl" placeholder="http://seaweedfs-s3:9327 (for scalable usage reporting)"/>
+          <a-form-item name="metricsUrl" ref="metricsUrl" :label="$t('label.seaweedfs.metrics.url')">
+            <a-input v-model:value="form.metricsUrl" :placeholder="$t('label.seaweedfs.metrics.url.placeholder')"/>
           </a-form-item>
           <a-form-item name="size" ref="size">
             <template #label>