Full test infrastructure, code audit fixes, and real E2E integration tests

Test infrastructure:
- Django standalone test runner (pytest-django, test settings, EmailUser model)
- React unit tests via Vitest with jsdom, jest compat layer, path aliases
- Playwright E2E tests using generated hooks in a real Chromium browser
- Docker Compose test backend (Django + Redis) for integration testing
- Desktop integration test app (PyWebView + Django + uvicorn)
- Makefile with test/test-django/test-react/test-integration targets

Library bugs found and fixed:
- hasJWT truthiness: undefined !== null was true, skipping session init
- process.env crash: CSR client referenced process.env in non-Node browsers
- baseUrl not forwarded: DjareaProvider didn't pass baseUrl to CSR client
- Relative URL handling: new URL() failed with relative base paths
- call() race condition: HTTP requests fired before CSRF cookie was set
- Session init await: added sessionRef promise so call() waits for session
- path_prefix on schema export: both export commands failed with URL reverse
- NullBooleanField removed: referenced field doesn't exist in Django 5.0+
- lru_cache on JWT settings: get_settings() now cached as intended
- Channel message routing: broadcasts now include channel name and params
- httpFunctionCall: fixed URL and request body format

Generator fixes:
- Removed 1,100 lines of REST/OpenAPI client generation (not part of Djarea)
- Generator now works for djarea-only projects without django-ninja REST APIs
- Generated DjangoContext now includes ChannelProvider when channels exist
- Fixed env var passthrough for schema export commands
- Deduplicated fetch logic into single runDjangoCommand helper

Test quality:
- Fixed 33 tautological Django tests with real assertions
- Found hidden bug: benchmark functions were never registered
- Found hidden bug: unicode lookalike test used plain ASCII
- Deleted worthless React unit tests (duplicates, shape checks, Zod-tests-Zod)
- Replaced jsdom integration tests with Playwright browser tests

Example apps:
- example/: Integration test backend with 33 server functions, 5 forms,
  4 channels covering auth variations, contexts, class-based ServerFunction,
  error codes, DjareaFormMixin, formsets, and JWT
- desktop/: PyWebView desktop app with file system access, SQLite CRUD,
  system introspection, and 39 real HTTP integration tests

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

django/src/djarea/forms/validation_utils.py

@@ -0,0 +1,72 @@
+from typing import Any
+
+from django import forms
+from django.core.files.uploadedfile import UploadedFile
+from django.utils.datastructures import MultiValueDict
+
+from .schemas import (
+    FieldError,
+    FieldErrorList,
+    FormValidation,
+    FormsetValidation,
+)
+from .schema_utils import create_form_instance
+
+
+def validate_form_instance(
+    form_class: type[forms.BaseForm],
+    data: dict,
+    files: MultiValueDict[str, UploadedFile] | None = None,
+    **kwargs: Any,
+) -> tuple[forms.BaseForm, FormValidation]:
+    """
+    Build a form instance and return (form, structured_validation_errors).
+    """
+    form = create_form_instance(form_class, data=data, files=files, initial=data, **kwargs)
+
+    # Run validation
+    form.is_valid()
+
+    validation = FormValidation(
+        errors=[
+            FieldErrorList(
+                field=field_name,
+                errors=[
+                    FieldError(
+                        message=str(e.message) if hasattr(e, 'message') else str(e),
+                        code=getattr(e, "code", None),
+                    )
+                    for e in field_errors.as_data()
+                ],
+            )
+            for field_name, field_errors in form.errors.items()
+        ]
+    )
+    return form, validation
+
+
+def build_formset_validation(formset: forms.BaseFormSet) -> FormsetValidation:
+    """
+    Turn a Django formset into a FormsetValidation structure.
+    """
+    return FormsetValidation(
+        general=[str(e) if e else "" for e in formset.non_form_errors()],
+        per_form=[
+            FormValidation(
+                errors=[
+                    FieldErrorList(
+                        field=field_name,
+                        errors=[
+                            FieldError(
+                                message=str(e.message) if hasattr(e, 'message') else str(e),
+                                code=getattr(e, "code", None),
+                            )
+                            for e in field_errors.as_data()
+                        ],
+                    )
+                    for field_name, field_errors in form.errors.items()
+                ]
+            )
+            for form in formset
+        ],
+    )