Rename djarea to mizan and fix React casing conventions

Rename the package from djarea to mizan across the entire codebase —
Python package, React library, generators, tests, and examples. Fix
JSX/hook casing (MizanProvider, useMizan, etc.) that broke when the
original PascalCase names were lowercased during the rename.

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

example/testapp/urls.py

@@ -1,5 +1,5 @@
 from django.urls import include, path
 
 urlpatterns = [
-    path("api/djarea/", include("djarea.urls")),
+    path("api/mizan/", include("mizan.urls")),
 ]