migrate to table based tinydb

NOTE to migrate database install tinydb & run migrate.py

- added new functions to filter data with db queries
- in the storage module

webapp/routes/archive.py

@@ -2,18 +2,14 @@
 from __future__ import annotations
 import time
 from flask import Blueprint, render_template, redirect, url_for
-from webapp.storage.orders import load_orders, update_order
+from webapp.storage.orders import load_archived, mark_archived
 
 bp = Blueprint("archive", __name__)
 
 @bp.get("/archiv")
 def archive_index():
     """Zeigt ausschließlich Aufträge mit status == 'archived'."""
-    archived = [o for o in load_orders() if o.get("status") == "archived"]
-    archived.sort(
-        key=lambda o: (o.get("archived_at") or o.get("done_at") or o.get("created_at") or ""),
-        reverse=True,
-    )
+    archived = load_archived()
     return render_template("archive.html", archived_orders=archived)
 
 @bp.post("/archiv/add/<order_id>")
@@ -23,5 +19,5 @@ def archive_add(order_id: str):
     Danach BLEIBEN wir auf der Strukturen-Seite (kein Wechsel zur Archiv-Seite).
     """
     now = time.strftime("%Y-%m-%dT%H:%M:%S%z", time.gmtime())
-    update_order(order_id, {"status": "archived", "archived_at": now})
+    mark_archived(order_id)
     return redirect(url_for("structures.structures"))  # zurück zu /strukturen