Enable vue/return-in-computed-property and add explicit fallback returns

Co-Authored-By: Codex <codex@openai.com>

eslint.config.mjs

@@ -118,7 +118,7 @@ export default [
     rules: {
       "vue/multi-word-component-names": "off",
       "vue/no-side-effects-in-computed-properties": "off",
-      "vue/return-in-computed-property": "off",
+      "vue/return-in-computed-property": "error",
       "vue/no-parsing-error": "error",
       "vue/valid-v-else": "error",
       "vue/no-deprecated-v-on-native-modifier": "error",

src/components/Discover/Conformance/MoreModal.vue

@@ -195,6 +195,7 @@ const caseData = computed(() => {
     });
     return data;
   }
+  return [];
 });
 
 const columnData = computed(() => {

src/components/Discover/Map/Filter/Attributes.vue

@@ -428,8 +428,9 @@ const valueData = computed(() => {
         item.type === selectedAttName.value.type &&
         item.key === selectedAttName.value.key,
     );
-    return data;
+    return data ?? null;
   }
+  return null;
 });
 
 // Compute slider data; time format: millisecond timestamps

src/components/Navbar.vue

@@ -177,6 +177,8 @@ const disabledSave = computed(() => {
       return !(
         conformanceFilterTempCheckId.value || conformanceLogTempCheckId.value
       );
+    default:
+      return true;
   }
 });
 

src/views/Files/Files.vue

@@ -560,6 +560,7 @@ const allFiles = computed(() => {
     );
     return sortFiles;
   }
+  return [];
 });
 
 /**