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

app/main.py

@@ -0,0 +1,22 @@
+from fastapi import FastAPI
+
+from app.api.health import router as health_router
+from app.api.stats import router as stats_router
+from app.api.tasks import router as tasks_router
+
+
+def create_app() -> FastAPI:
+    app = FastAPI(
+        title="TaskFlow",
+        version="1.0.0",
+    )
+
+    app.include_router(health_router)
+    app.include_router(tasks_router)
+    app.include_router(stats_router)
+
+    return app
+
+
+app = create_app()
+