fix: separate HWID device renewal flows

Keep one-off device top-ups scoped to the active subscription term and move device renewal into subscription checkout.

Carry HWID renewal metadata through provider callbacks and webhooks, including YooKassa saved-card flows.

Add admin extension controls, docs, demo data, and regression coverage.

backend/bot/payment_providers/shared/common.py

@@ -100,6 +100,11 @@ def build_payment_record_payload(
     base = sale_mode_base(sale_mode)
     is_traffic = sale_mode_is_traffic(sale_mode)
     is_hwid = sale_mode_is_hwid_devices(sale_mode)
+    hwid_devices = int(float(months)) if is_hwid else None
+    if hwid_quote:
+        quote_devices = parse_positive_int_units(hwid_quote.get("device_count"))
+        if quote_devices is not None:
+            hwid_devices = quote_devices
     payload = {
         "user_id": user_id,
         "amount": amount,
@@ -111,9 +116,9 @@ def build_payment_record_payload(
         "sale_mode": sale_mode,
         "tariff_key": sale_mode_tariff_key(sale_mode),
         "purchased_gb": float(months) if is_traffic else None,
-        "purchased_hwid_devices": int(float(months)) if is_hwid else None,
+        "purchased_hwid_devices": hwid_devices,
     }
-    if hwid_quote and is_hwid:
+    if hwid_quote and hwid_devices is not None:
         payload.update(
             {
                 "hwid_valid_from": hwid_quote.get("valid_from"),
@@ -164,14 +169,20 @@ def payment_record_amounts(
     months: Any,
     sale_mode: str,
     traffic_gb: Optional[float] = None,
+    hwid_device_count: Optional[int] = None,
 ) -> PaymentRecordAmounts:
     traffic_sale = sale_mode_is_traffic(sale_mode)
     hwid_devices_sale = sale_mode_is_hwid_devices(sale_mode)
     units = traffic_gb if traffic_sale and traffic_gb is not None else months
+    purchased_hwid_devices = int(float(months)) if hwid_devices_sale else None
+    if not hwid_devices_sale and hwid_device_count is not None:
+        parsed_hwid_devices = parse_positive_int_units(hwid_device_count)
+        if parsed_hwid_devices is not None:
+            purchased_hwid_devices = parsed_hwid_devices
     return PaymentRecordAmounts(
         months=int(float(units)) if traffic_sale else int(float(months)),
         purchased_gb=float(units) if traffic_sale else None,
-        purchased_hwid_devices=int(float(months)) if hwid_devices_sale else None,
+        purchased_hwid_devices=purchased_hwid_devices,
         tariff_key=sale_mode_tariff_key(sale_mode),
         traffic_sale=traffic_sale,
         hwid_devices_sale=hwid_devices_sale,
@@ -281,6 +292,7 @@ async def create_webapp_payment_record(
         months=ctx.months,
         sale_mode=ctx.sale_mode,
         traffic_gb=ctx.traffic_gb,
+        hwid_device_count=ctx.hwid_device_count,
     )
     return await create_base_payment_record(
         ctx.session,