fix(tibber): fetch newest price slots via priceInfoRange last:192

priceInfoRange is a Relay-style cursor connection over the subscription's
entire price history. With no cursor, first:96 returned the OLDEST 96 slots,
anchored at the subscription start date — a fixed window that never advanced.
For a contract added mid-period this meant refresh_prices kept re-upserting the
same day-one slots forever, so GET /api/energy/prices found nothing in the
today+tomorrow window and the UI showed "No Tibber price points available".

Use last:192 to return the newest 192 quarter-hourly slots (2 days), which ends
at the latest published slot and advances daily, fully covering the prices
endpoint's today+tomorrow window.

app/integrations/tibber/client.py

@@ -31,18 +31,24 @@ _TIBBER_API_URL = "https://api.tibber.com/v1-beta/gql"
 _DEFAULT_TIMEOUT = 15.0
 
 # GraphQL query to fetch a range of 15-minute price nodes.
-# ``priceInfoRange(resolution: QUARTER_HOURLY, first: 96)`` fetches up to
+# ``priceInfoRange`` is a Relay-style cursor connection over the subscription's
-# 96 quarter-hourly slots which covers today + tomorrow (2 × 24 × 4 = 192 max,
+# entire available price history.  With no before/after cursor:
-# but the Tibber API typically starts from the current slot and returns at
+#   * ``first: N`` returns the OLDEST N nodes (anchored at the subscription
-# most the remaining hours of today plus tomorrow, so 96 is a good cap for
+#     start date) — a fixed window that never advances, so it is WRONG for
-# "today + tomorrow").
+#     "current + upcoming" prices.
+#   * ``last: N`` returns the NEWEST N nodes (ending at the latest published
+#     slot: tomorrow 23:45 once day-ahead prices are out, else today 23:45).
+# We want the newest slots, so we use ``last``.  192 = 2 days × 24 h × 4 slots,
+# which fully covers the "today + tomorrow" window that GET /api/energy/prices
+# queries (the earliest of the 192 newest slots reaches back past today 00:00
+# UTC in either publish state).
 _PRICE_RANGE_QUERY = """
 {
   viewer {
     homes {
       id
       currentSubscription {
-        priceInfoRange(resolution: QUARTER_HOURLY, first: 96) {
+        priceInfoRange(resolution: QUARTER_HOURLY, last: 192) {
           nodes {
             startsAt
             total
@@ -232,9 +238,11 @@ def fetch_price_range(
 ) -> list[PricePoint]:
     """Fetch a range of 15-minute price nodes from the Tibber API.
 
-    Sends the ``priceInfoRange(resolution: QUARTER_HOURLY, first: 96)`` query
+    Sends the ``priceInfoRange(resolution: QUARTER_HOURLY, last: 192)`` query
-    and parses every returned node into a ``PricePoint``.  The number of nodes
+    and parses every returned node into a ``PricePoint``.  ``last`` (not
-    is not assumed — all returned nodes are parsed regardless of count.
+    ``first``) is used so the newest slots are returned; ``first`` would anchor
+    at the subscription start date and never advance.  The number of nodes is
+    not assumed — all returned nodes are parsed regardless of count.
 
     Parameters
     ----------