feat(taskflow): add core task API, storage persistence, csv export, stats page, and test coverage

app/storage/factory.py

@@ -0,0 +1,16 @@
+from __future__ import annotations
+
+from pathlib import Path
+
+from app.storage.repository import JsonFileTaskRepository
+
+
+DEFAULT_DATA_DIR = Path("data")
+DEFAULT_TASKS_FILE = DEFAULT_DATA_DIR / "tasks.json"
+
+
+def create_task_repository(
+    file_path: str | Path = DEFAULT_TASKS_FILE,
+) -> JsonFileTaskRepository:
+    return JsonFileTaskRepository(file_path=file_path)
+