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>

Makefile

@@ -20,7 +20,7 @@ test-react:
 
 test-integration: docker-up
 	@echo "Waiting for backend..."
-	@timeout 30 sh -c 'until curl -sf http://localhost:8000/api/djarea/session/ > /dev/null 2>&1; do sleep 1; done'
+	@timeout 30 sh -c 'until curl -sf http://localhost:8000/api/mizan/session/ > /dev/null 2>&1; do sleep 1; done'
 	cd react && npm run test:integration
 	@$(MAKE) docker-down
 
@@ -41,6 +41,6 @@ test-all: test test-integration
 
 clean:
 	docker compose -f docker-compose.test.yml down -v --remove-orphans 2>/dev/null || true
-	rm -rf django/src/djarea.egg-info django/dist django/build
+	rm -rf django/src/mizan.egg-info django/dist django/build
 	rm -rf react/dist react/node_modules
 	rm -f example/db.sqlite3