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/components/base/BaseFileUploader.vue

@@ -441,7 +441,7 @@ let currentStatus = ref(null)
 
 function reset() {
   // reset form to initial state
-  currentStatus = STATUS_INITIAL
+  currentStatus.value = STATUS_INITIAL
 
   uploadedFiles.value = []
 
@@ -451,7 +451,7 @@ function reset() {
     localFiles.value = []
   }
 
-  uploadError = null
+  uploadError.value = null
 }
 
 function upload(formData) {
@@ -467,16 +467,16 @@ function upload(formData) {
 
 // upload data to the server
 function save(formData) {
-  currentStatus = STATUS_SAVING
+  currentStatus.value = STATUS_SAVING
 
   upload(formData)
     .then((x) => {
-      uploadedFiles = [].concat(x)
-      currentStatus = STATUS_SUCCESS
+      uploadedFiles.value = [].concat(x)
+      currentStatus.value = STATUS_SUCCESS
     })
     .catch((err) => {
-      uploadError = err.response
-      currentStatus = STATUS_FAILED
+      uploadError.value = err.response
+      currentStatus.value = STATUS_FAILED
     })
 }