fix(frontend): keep the API client's shapes under orval 8 and regenerate it

frontend/app/orval.config.ts

@@ -1,5 +1,9 @@
 import { defineConfig } from 'orval';
 
+// Orval 8 settings that keep the client's orval 6 shapes. Leave
+// override.query.useQuery/useMutation unset: orval 8 applies them to every
+// verb, and a GET with both becomes a mutation. Unset, GETs get query hooks
+// and the other verbs get mutation hooks.
 export default defineConfig({
   dataing: {
     input: {
@@ -10,16 +14,31 @@ export default defineConfig({
       target: 'src/lib/api/generated',
       schemas: 'src/lib/api/model',
       client: 'react-query',
+      // customInstance takes one request config ({ url, method, params, data,
+      // signal }), which is what the axios client passes to a mutator. The
+      // default fetch client would call it as (url, init). Nothing imports
+      // axios: customInstance makes the request.
+      httpClient: 'axios',
       mock: false,
+      // Orval 6 sorted model properties alphabetically.
+      propertySortOrder: 'Alphabetical',
+      // Orval picks import extensions from tsconfig.json, where Vite's
+      // allowImportingTsExtensions makes it write "../../client.ts". The same
+      // module settings without that flag keep imports extensionless.
+      tsconfig: {
+        compilerOptions: {
+          module: 'ESNext',
+          moduleResolution: 'bundler',
+        },
+      },
       override: {
         mutator: {
           path: './src/lib/api/client.ts',
           name: 'customInstance',
         },
-        query: {
-          useQuery: true,
-          useMutation: true,
-        },
+        // Orval 6 named nullable property types (FooBar = string | null);
+        // orval 8 inlines them unless this is set.
+        aliasCombinedTypes: true,
       },
     },
     hooks: {