test(10-05): bring every SPA module, composable and component under Vitest

- 41 unit and component suites under admin/tests/{app,state,shell,list,form,relation,views,ui}
  covering states and a11y roles; every src module is imported by a test
- typed fixture helper assigns each JSON fixture to its generated OpenAPI type
- fix: iconFor ignores inherited object members such as "constructor"
- fix: field controls import ./control instead of the registry (import cycle
  left a renderer unregistered depending on module load order)
- fix: dropdown shows the placeholder for an unknown stored value next to an emptyOption
- fix: list announces a failed schema load even when the rows arrive after it
- tailwind no longer scans admin/tests; boardwalk/dist rebuilt

admin/src/components/form/fields/SwitchField.vue

@@ -1,6 +1,6 @@
 <script setup lang="ts">
 import { computed } from 'vue'
-import { toggleOn, toggleValue, type FieldControlProps } from '../registry'
+import { toggleOn, toggleValue, type FieldControlProps } from '../control'
 
 // Toggle card (design screen 4): the label as title, the comment as helper
 // text and a 44x26 role="switch" control; the off track uses borderStrong.