feat(10-03): open, edit and save a record with toast and 422 feedback

- The SPA loads the backend::lang bundle before /auth/me, sets the
  document language from meta.locale and renders plural messages with
  Intl.PluralRules; interpolate mirrors phrasebook for :name/:Name/:NAME
- Create and record routes; mapWinterUrl maps recordUrl and redirects
  onto the controller's list, create and record routes only
- List rows open their record; FormView loads the form schema and the
  record, shows context-allowed fields in the span grid, saves values
  keyed by field name and toasts the resolved saved message
- A 422 puts each message under its field (aria-invalid,
  aria-describedby), shows the plural banner, focuses the first invalid
  field in schema order and clears a field's error on change
- The D-05 registry maps text, textarea, number and dropdown; any other
  type renders the unsupported-field box with the type in DM Mono
- The admin OpenAPI document declares the write request bodies
  (AdminRecord, AdminIDsRequest) and the list filter query as a
  deepObject, so the typed client can send them
- New backend::lang form.load_failed key; boardwalk/dist rebuilt

admin/src/main.ts

@@ -2,11 +2,15 @@ import { createApp } from 'vue'
 import App from './App.vue'
 import { createAdminRouter } from './app/router'
 import { onUnauthorized } from './api/client'
+import { loadStrings } from './app/i18n'
 import { clearUser, me } from './state/useAuth'
 import { loadNavigation } from './state/useNavigation'
 import './styles/main.css'
 
 async function boot(): Promise<void> {
+  // Boot order (research Pattern 7): the public strings bundle first, so the
+  // login screen is translated, then the session, then navigation.
+  await loadStrings().catch(() => undefined)
   // A 401 here only means "not signed in"; the router guard sends the
   // visitor to the login route with the requested path as redirect.
   const user = await me().catch(() => null)