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>

react/src/errors.ts

@@ -0,0 +1,107 @@
+/**
+ * Django Server Error Types
+ *
+ * Typed errors for server function failures.
+ */
+
+/**
+ * Error codes returned by the server
+ */
+export type ErrorCode =
+    | 'NOT_FOUND'
+    | 'VALIDATION_ERROR'
+    | 'UNAUTHORIZED'
+    | 'FORBIDDEN'
+    | 'BAD_REQUEST'
+    | 'INTERNAL_ERROR'
+    | 'NOT_IMPLEMENTED'
+
+/**
+ * Error response structure from the server
+ */
+export interface FunctionErrorResponse {
+    error: true
+    code: ErrorCode
+    message: string
+    details?: {
+        fields?: Record<string, string[]>
+        required?: string[]
+        type?: string
+        [key: string]: unknown
+    }
+}
+
+/**
+ * Error thrown when a server function call fails
+ */
+export class DjangoError extends Error {
+    /**
+     * Error code from the server
+     */
+    readonly code: ErrorCode
+
+    /**
+     * Additional error details
+     */
+    readonly details?: FunctionErrorResponse['details']
+
+    /**
+     * The original error response
+     */
+    readonly response: FunctionErrorResponse
+
+    constructor(response: FunctionErrorResponse) {
+        super(response.message)
+        this.name = 'DjangoError'
+        this.code = response.code
+        this.details = response.details
+        this.response = response
+
+        // Maintains proper stack trace for where error was thrown
+        if (Error.captureStackTrace) {
+            Error.captureStackTrace(this, DjangoError)
+        }
+    }
+
+    /**
+     * Check if this is a validation error
+     */
+    isValidationError(): boolean {
+        return this.code === 'VALIDATION_ERROR'
+    }
+
+    /**
+     * Check if this is an authentication error
+     */
+    isAuthError(): boolean {
+        return this.code === 'UNAUTHORIZED' || this.code === 'FORBIDDEN'
+    }
+
+    /**
+     * Check if this is a not found error
+     */
+    isNotFound(): boolean {
+        return this.code === 'NOT_FOUND'
+    }
+
+    /**
+     * Get field-level validation errors (if this is a validation error)
+     */
+    getFieldErrors(): Record<string, string[]> | null {
+        if (this.code === 'VALIDATION_ERROR' && this.details?.fields) {
+            return this.details.fields
+        }
+        return null
+    }
+
+    /**
+     * Get error for a specific field
+     */
+    getFieldError(field: string): string | null {
+        const errors = this.getFieldErrors()
+        if (errors && errors[field]?.length > 0) {
+            return errors[field][0]
+        }
+        return null
+    }
+}