Rename all djarea references to mizan

- djarea_clients.py → clients.py (both example apps)
- export_djarea_schema → export_mizan_schema (management command)
- djarea.spec.ts → mizan.spec.ts (playwright test)
- fetch.mjs: command name updated
- apps.py/asgi.py: import paths updated
- Removed stale generated.djarea.* artifacts
- Fixed desktop app: asgi.py import, vite config aliases, package.json dep path

373 Django tests pass. Both example apps verified running.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/mizan-django/generate/generator/lib/fetch.mjs

@@ -84,5 +84,5 @@ export async function fetchMizanSchema(source, cwd) {
   if (!source.django) {
     throw new Error('mizan schema export requires django source configuration')
   }
-  return runDjangoCommand(source, cwd, 'export_djarea_schema')
+  return runDjangoCommand(source, cwd, 'export_mizan_schema')
 }