Next-level improvements: 15 items across backend, frontend, and testing

Backend:
- SQLiteStateBackend: persistent task/trace storage with SQLite
- InMemoryStateBackend: in-memory impl of StateBackend interface
- Redis cache backend (CacheBackend ABC + MemoryCacheBackend + RedisCacheBackend)
- OpenAI adapter: async acomplete() with retry logic
- Per-tenant + per-IP rate limiting in middleware

Frontend:
- State management: useStore + useAppState (zero-dep, context + reducer)
- React Router integration: URL-based navigation (usePageNavigation)
- WebSocket streaming: sendPrompt + StreamCallbacks for token-by-token updates
- File preview: inline image/text/binary preview with expand/collapse
- Sparkline charts + MetricCard + BarChart for dashboard visualization
- Push notifications hook (useNotifications) with browser Notification API
- i18n system: 6 locales (en, es, fr, de, ja, zh) with interpolation
- 6 new Storybook stories (ChatMessage, Skeleton, Markdown, SearchFilter, Toast, FilePreview)

Testing:
- Playwright E2E config + 6 browser specs (desktop + mobile)
- 18 new Python tests (SQLiteStateBackend, InMemoryStateBackend, cache backends)

570 Python tests + 45 frontend tests = 615 total, 0 ruff errors.

Co-Authored-By: Nakamoto, S <defi@defi-oracle.io>

fusionagi/adapters/openai_adapter.py

@@ -213,6 +213,57 @@ class OpenAIAdapter(LLMAdapter):
             raise self._classify_error(last_error) from last_error
         raise OpenAIAdapterError("All retries exhausted with unknown error")
 
+    async def acomplete(
+        self,
+        messages: list[dict[str, str]],
+        **kwargs: Any,
+    ) -> str:
+        """Async version of complete using OpenAI's async client.
+
+        Args:
+            messages: List of message dicts with 'role' and 'content'.
+            **kwargs: Additional arguments for the API call.
+
+        Returns:
+            The assistant's response content.
+        """
+        import asyncio
+
+        if not messages:
+            return ""
+
+        try:
+            import openai
+        except ImportError as e:
+            raise ImportError("Install with: pip install fusionagi[openai]") from e
+
+        async_client = openai.AsyncOpenAI(api_key=self._api_key, **self._client_kwargs)
+        model = kwargs.pop("model", self._model)
+        last_error: Exception | None = None
+        delay = self._retry_delay
+
+        for attempt in range(self._max_retries + 1):
+            try:
+                response = await async_client.chat.completions.create(
+                    model=model, messages=messages, **kwargs  # type: ignore[arg-type]
+                )
+                content = response.choices[0].message.content or ""
+                return content
+            except Exception as e:
+                last_error = e
+                if not self._is_retryable_error(e) or attempt == self._max_retries:
+                    break
+                logger.warning(
+                    "OpenAI async retry",
+                    extra={"attempt": attempt + 1, "error": str(e), "delay": delay},
+                )
+                await asyncio.sleep(delay)
+                delay = min(delay * self._retry_multiplier, self._max_retry_delay)
+
+        if last_error is not None:
+            raise self._classify_error(last_error) from last_error
+        raise OpenAIAdapterError("All retries exhausted")
+
     def complete_structured(
         self,
         messages: list[dict[str, str]],