feat: add wiki.gg as a second Endfield source

First non-Game8 parser, and the first source that states region-scoped ends:
wiki.gg emits ISO timestamps with one timer per server region, so Endfield
events now carry exact times and separate Asia / Americas-Europe ends. That
gap is up to 13 hours, which is what regionEnds was built for.

Two sources for one game also exercised merge for real. It caught both
overlaps — including "Bedazzling Dawnstar" against Game8's "Bedazzling
Dawnstar Sign-In" — and flagged that the two disagree on the end date by 70
hours rather than averaging them into a date neither states.

Matching an appended qualifier needed a prefix test, not a subset test: a
subset would also fuse "Gold Clash" with "Gold Rush Clash Royale".

Also fixes build-feed picking fixtures by game rather than by source, which
handed the wiki.gg page to the Game8 parser once Endfield had two.

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

src/ingest/adapters/index.ts

@@ -50,6 +50,15 @@ const SOURCES: SourceSpec[] = [
     url: "https://game8.co/games/Arknights-Endfield/archives/535443",
     parserId: "game8",
   },
+  {
+    id: "endfield-wikigg-events",
+    game: "endfield",
+    url: "https://endfield.wiki.gg/wiki/Event",
+    parserId: "wikigg",
+    // Exact timestamps and per-region ends beat Game8's day-precision prose,
+    // so this source wins when the two disagree.
+    priority: 10,
+  },
   {
     id: "nte-game8-events",
     game: "nte",