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>

Dockerfile.test

@@ -7,7 +7,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     gcc \
     && rm -rf /var/lib/apt/lists/*
 
-# Install djarea from local source with channels support
+# Install mizan from local source with channels support
 COPY django/ /app/django/
 RUN pip install --no-cache-dir /app/django[channels] daphne