feat: add Arknights: Endfield, and stop passing off requirements as summaries

Endfield was previously written off as undatable. That was wrong: a first
pass only inspected its Duration rows (all "Permanently Available") and its
year-less version grid, and missed an "Event | Schedule & Summary" table
whose cells read "Period: 08/09/26 - 08/30/26 During the event...". Two real
events, with a year.

Adds MM/DD/YY range parsing for that shape. Month-first ordering is not
assumed lightly — Endfield's own version grid reads 01/22, 04/17, 07/16 for
versions 1.0, 1.2 and 1.4, chronological only if the month comes first.

Also stops presenting unlock conditions as descriptions. Several templates
put "Reach Union Level 8" where a blurb would go; filling the summary slot
with text that never says what the event is is worse than leaving it empty.
Wuthering Waves correctly drops to zero summaries as a result.

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

src/ingest/adapters/index.ts

@@ -44,6 +44,12 @@ const SOURCES: SourceSpec[] = [
     url: "https://game8.co/games/Zenless-Zone-Zero/archives/457176",
     parserId: "game8",
   },
+  {
+    id: "endfield-game8-events",
+    game: "endfield",
+    url: "https://game8.co/games/Arknights-Endfield/archives/535443",
+    parserId: "game8",
+  },
   {
     id: "nte-game8-events",
     game: "nte",