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/components/currency-exchange-rate/ExchangeRateBulkUpdate.vue

@@ -11,7 +11,7 @@
       }}
     </p>
 
-    <form action="" @submit.prevent="submitBulkUpdate">
+    <form id="bulk-update-form" action="" @submit.prevent="submitBulkUpdate">
       <ValidateEach
         v-for="(c, i) in exchangeRateStore.bulkCurrencies"
         :key="i"
@@ -50,22 +50,21 @@
           </BaseInputGroup>
         </template>
       </ValidateEach>
+    </form>
+
+    <template #footer>
       <div
-        slot="footer"
         class="
           z-0
           flex
           justify-end
-          mt-4
-          pt-4
-          border-t border-gray-200 border-solid
         "
       >
-        <BaseButton :loading="isSaving" variant="primary" type="submit">
+        <BaseButton :loading="isSaving" variant="primary" type="submit" form="bulk-update-form">
           {{ $t('general.save') }}
         </BaseButton>
       </div>
-    </form>
+    </template>
   </BaseCard>
 </template>
 

resources/scripts/admin/components/estimate-invoice-common/CreateItemRowTax.vue

@@ -106,7 +106,7 @@ const props = defineProps({
   },
   taxes: {
     type: Array,
-    default: [],
+    default: () => [],
   },
   total: {
     type: Number,

resources/scripts/admin/components/estimate-invoice-common/SalesTax.vue

@@ -79,6 +79,7 @@ const addressData = computed(() => {
       address: pick(address, ['address_street_1', 'city', 'state', 'zip']),
     }
   }
+  return null
 })
 
 const isAddressAvailable = computed(() => {