refactor(frontend): comprehensive split of large view files into modular components

- Split UsersView.vue into UserCreateModal, UserEditModal, UserApiKeysModal, etc.
- Split UsageView.vue into UsageStatsCards, UsageFilters, UsageTable, etc.
- Split DashboardView.vue into UserDashboardStats, UserDashboardCharts, etc.
- Split AccountsView.vue into AccountTableActions, AccountTableFilters, etc.
- Standardized TypeScript types across new components to resolve implicit 'any' and 'never[]' errors.
- Improved overall frontend maintainability and code clarity.

frontend/src/components/user/profile/ProfileEditForm.vue

@@ -0,0 +1,74 @@
+<template>
+  <div class="card">
+    <div class="border-b border-gray-100 px-6 py-4 dark:border-dark-700">
+      <h2 class="text-lg font-medium text-gray-900 dark:text-white">
+        {{ t('profile.editProfile') }}
+      </h2>
+    </div>
+    <div class="px-6 py-6">
+      <form @submit.prevent="handleUpdateProfile" class="space-y-4">
+        <div>
+          <label for="username" class="input-label">
+            {{ t('profile.username') }}
+          </label>
+          <input
+            id="username"
+            v-model="username"
+            type="text"
+            class="input"
+            :placeholder="t('profile.enterUsername')"
+          />
+        </div>
+
+        <div class="flex justify-end pt-4">
+          <button type="submit" :disabled="loading" class="btn btn-primary">
+            {{ loading ? t('profile.updating') : t('profile.updateProfile') }}
+          </button>
+        </div>
+      </form>
+    </div>
+  </div>
+</template>
+
+<script setup lang="ts">
+import { ref, watch } from 'vue'
+import { useI18n } from 'vue-i18n'
+import { useAuthStore } from '@/stores/auth'
+import { useAppStore } from '@/stores/app'
+import { userAPI } from '@/api'
+
+const props = defineProps<{
+  initialUsername: string
+}>()
+
+const { t } = useI18n()
+const authStore = useAuthStore()
+const appStore = useAppStore()
+
+const username = ref(props.initialUsername)
+const loading = ref(false)
+
+watch(() => props.initialUsername, (val) => {
+  username.value = val
+})
+
+const handleUpdateProfile = async () => {
+  if (!username.value.trim()) {
+    appStore.showError(t('profile.usernameRequired'))
+    return
+  }
+
+  loading.value = true
+  try {
+    const updatedUser = await userAPI.updateProfile({
+      username: username.value
+    })
+    authStore.user = updatedUser
+    appStore.showSuccess(t('profile.updateSuccess'))
+  } catch (error: any) {
+    appStore.showError(error.response?.data?.detail || t('profile.updateFailed'))
+  } finally {
+    loading.value = false
+  }
+}
+</script>