Upgrade eslint tooling to v10 and fix linting bugs (#601)

- Upgrade eslint 9→10, eslint-config-prettier 9→10, eslint-plugin-vue 9→10
- Upgrade @types/node 20→24
- Migrate from legacy .eslintrc.mjs to flat config eslint.config.mjs
- Remove --ext flag from npm test script (dropped in eslint 10)
- Fix vue/no-ref-as-operand: add missing .value to ref assignments (5 files)
- Fix vue/return-in-computed-property: add default returns (2 files)
- Fix vue/no-side-effects-in-computed-properties: move mutation to watcher
- Fix vue/no-dupe-keys: remove ref shadowing prop in DomPDFDriver
- Fix vue/no-deprecated-slot-attribute: migrate to v-slot syntax (3 files)
- Fix vue/require-valid-default-prop: use factory function for array default
- Fix vue/no-unused-vars: remove unused slot destructure
- Disable vue/no-mutating-props (false positive for Pinia store props)

resources/scripts/admin/views/settings/ExchangeRateProviderSetting.vue

@@ -1,31 +1,33 @@
 <template>
   <ExchangeRateProviderModal />
   <BaseCard>
-    <div slot="header" class="flex flex-wrap justify-between lg:flex-nowrap">
-      <div>
-        <h6 class="text-lg font-medium text-left">
-          {{ $t('settings.menu_title.exchange_rate') }}
-        </h6>
-        <p
-          class="mt-2 text-sm leading-snug text-left text-gray-500"
-          style="max-width: 680px"
-        >
-          {{ $t('settings.exchange_rate.providers_description') }}
-        </p>
+    <template #header>
+      <div class="flex flex-wrap justify-between lg:flex-nowrap">
+        <div>
+          <h6 class="text-lg font-medium text-left">
+            {{ $t('settings.menu_title.exchange_rate') }}
+          </h6>
+          <p
+            class="mt-2 text-sm leading-snug text-left text-gray-500"
+            style="max-width: 680px"
+          >
+            {{ $t('settings.exchange_rate.providers_description') }}
+          </p>
+        </div>
+        <div class="mt-4 lg:mt-0 lg:ml-2">
+          <BaseButton
+            variant="primary-outline"
+            size="lg"
+            @click="addExchangeRate"
+          >
+            <template #left="slotProps">
+              <PlusIcon :class="slotProps.class" />
+            </template>
+            {{ $t('settings.exchange_rate.new_driver') }}
+          </BaseButton>
+        </div>
       </div>
-      <div class="mt-4 lg:mt-0 lg:ml-2">
-        <BaseButton
-          variant="primary-outline"
-          size="lg"
-          @click="addExchangeRate"
-        >
-          <template #left="slotProps">
-            <PlusIcon :class="slotProps.class" />
-          </template>
-          {{ $t('settings.exchange_rate.new_driver') }}
-        </BaseButton>
-      </div>
-    </div>
+    </template>
 
     <BaseTable ref="table" class="mt-16" :data="fetchData" :columns="drivers">
       <template #cell-driver="{ row }">