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>

e2e/djarea.spec.ts

@@ -1,9 +1,9 @@
 /**
- * Djarea E2E Integration Tests
+ * mizan E2E Integration Tests
  *
  * Real Chromium → Real React app (generated hooks) → Real Django backend
  *
- * Every test uses the generated Djarea API, not raw call() or fetch().
+ * Every test uses the generated mizan API, not raw call() or fetch().
  */
 
 import { test, expect } from '@playwright/test'
@@ -150,7 +150,7 @@ test.describe('generated form hooks', () => {
         expect(result.fields.password).toBeDefined()
     })
 
-    test('useContactForm loads schema with DjareaFormMeta', async ({ page }) => {
+    test('useContactForm loads schema with mizanFormMeta', async ({ page }) => {
         await fixture(page, 'form-contact-schema')
         const result = await getResult(page)
         expect(result.title).toBe('Contact Us')