feat: add Stella Sora, from the wiki's front page rather than its banner list

This wiki publishes the same schedule twice and the fuller surface is the worse
one. /wiki/Banner_List has 55 clean rows with full wall clocks and states no
timezone anywhere on the page; the front page's Current Banners module emits
the same instants as real <time datetime="...-07:00"> elements. The two agree
exactly, which is strong evidence the list is UTC and is still only evidence —
so we read the surface that says what it means and pay four live banners
instead of a full history for it. If an editor ever states the zone on
Banner_List, that page becomes the better source immediately.

Two ways this could have failed silently. The template writes its BEM
underscores as &#95;&#95;, so a selector written against the class name a
browser shows matches nothing at all; and banner names are red links to
?action=edit&redlink=1, which Miraheze's robots.txt disallows, so a href
carrying a query is refused and the page URL stands in.

No resetOffsets, and here the source did state an offset: -07:00, which is US
Pacific and therefore shifts twice a year. That is the Fate/Grand Order gap
arriving through a page that looks like it answered the question.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>

docs/DATA-MODEL.md

@@ -10,7 +10,7 @@ import { z } from "zod";
 
 export const GameId = z.enum([
   "genshin", "hsr", "zzz", "wuwa", "arknights", "endfield", "nte", "nikki", "p5x", "r1999",
-  "ba", "fgo", "holodori", "gfl2",
+  "ba", "fgo", "holodori", "gfl2", "stellasora",
 ]);
 
 export const EventType = z.enum([
@@ -310,13 +310,18 @@ logged under the old clock. Get it right at introduction or accept a migration.
 
 Infinity Nikki, P5X and Blue Archive carry **no `resetOffsets`
 entry**, so they take the regional default. That is an assumption, not a verified server map — none
-of those sources states one. The 2026-08-19 addition below is worth separating out, because it is
-silent for a different reason than the usual one:
+of those sources states one. Two of the 2026-08-19 additions are worth separating out, because they
+are silent for different reasons and neither is the usual one:
 
 - **Girls' Frontline 2** states an exact UTC instant on every boundary, so the data is there and
   still settles nothing: its EN events end at 22:59 (33 of them), 08:59 (11) and 02:59 (5). Arknights
   and Reverse: 1999 each earned an override from a single boundary the whole page agreed on; three
   of them is a patch window, not a reset hour.
+- **Stella Sora** states an offset outright — `-07:00` — and that is precisely why it gets no entry.
+  `-07:00` is US Pacific in summer and `-08:00` in winter, so one fixed number is wrong for half the
+  year in either direction. This is the Fate/Grand Order gap, arriving through a source that looks
+  like it answered the question.
+
 
 Blue Archive is the case where the assumption is most likely wrong and still the right entry: the
 game does run one worldwide server, but `bluearchive.wiki` states no time of day and no timezone