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>

tests/test_sqlite_backend.py

@@ -0,0 +1,79 @@
+"""Tests for SQLiteStateBackend."""
+
+import os
+import tempfile
+
+import pytest
+
+from fusionagi.core.sqlite_backend import SQLiteStateBackend
+from fusionagi.schemas.task import Task, TaskState
+
+
+@pytest.fixture
+def db_path():
+    fd, path = tempfile.mkstemp(suffix=".db")
+    os.close(fd)
+    yield path
+    os.unlink(path)
+
+
+@pytest.fixture
+def backend(db_path):
+    return SQLiteStateBackend(db_path=db_path)
+
+
+def test_set_and_get_task(backend):
+    task = Task(task_id="t1", goal="test goal")
+    backend.set_task(task)
+    loaded = backend.get_task("t1")
+    assert loaded is not None
+    assert loaded.task_id == "t1"
+    assert loaded.goal == "test goal"
+
+
+def test_get_missing_task(backend):
+    assert backend.get_task("nonexistent") is None
+
+
+def test_task_state(backend):
+    task = Task(task_id="t2", goal="state test")
+    backend.set_task(task)
+    assert backend.get_task_state("t2") == TaskState.PENDING
+    backend.set_task_state("t2", TaskState.ACTIVE)
+    assert backend.get_task_state("t2") == TaskState.ACTIVE
+
+
+def test_traces(backend):
+    backend.set_task(Task(task_id="t3", goal="trace test"))
+    backend.append_trace("t3", {"step": 1, "action": "start"})
+    backend.append_trace("t3", {"step": 2, "action": "complete"})
+    traces = backend.get_trace("t3")
+    assert len(traces) == 2
+    assert traces[0]["step"] == 1
+    assert traces[1]["action"] == "complete"
+
+
+def test_list_tasks(backend):
+    for i in range(5):
+        t = Task(task_id=f"list-{i}", goal=f"goal {i}")
+        if i >= 3:
+            t = t.model_copy(update={"state": TaskState.ACTIVE})
+        backend.set_task(t)
+    all_tasks = backend.list_tasks()
+    assert len(all_tasks) == 5
+    active = backend.list_tasks(state=TaskState.ACTIVE)
+    assert len(active) == 2
+
+
+def test_delete_task(backend):
+    backend.set_task(Task(task_id="del-1", goal="delete me"))
+    backend.append_trace("del-1", {"action": "trace"})
+    assert backend.delete_task("del-1") is True
+    assert backend.get_task("del-1") is None
+    assert backend.get_trace("del-1") == []
+
+
+def test_count_tasks(backend):
+    assert backend.count_tasks() == 0
+    backend.set_task(Task(task_id="c1", goal="count"))
+    assert backend.count_tasks() == 1