fix(ingest): support redesigned Blue Archive wiki event table

The Blue Archive Wiki (bluearchive.wiki/wiki/Events) redesigned its
schedule, replacing the per-version MediaWiki tabber with a unified
#eventtable displaying JP and Global periods side-by-side.

- Parse #eventtable resolving GL Period, event titles, and article links
  from .event-region-gl, with fallback to .event-region-jp.
- Maintain backwards compatibility with legacy tabber schedule format.
- Add pinned fixture fixtures/ba/bawiki-events-2026-09-17 and tests.
- Update snapshot, AGENTS.md, ARCHITECTURE.md, and INGESTION.md.

fixtures/ba/bawiki-events-2026-09-17.expected.json

@@ -0,0 +1,107 @@
+[
+  {
+    "id": "ba:code-box-the-shadow-approaching-millennium:2026-08-04",
+    "game": "ba",
+    "title": "Code: BOX - The Shadow Approaching Millennium",
+    "type": "rerun",
+    "summary": "Rerun",
+    "startsAt": "2026-08-04T00:00:00.000Z",
+    "startPrecision": "day",
+    "endsAt": "2026-08-18T00:00:00.000Z",
+    "endPrecision": "day",
+    "regionScoped": false,
+    "regionEnds": null,
+    "sourceUrl": "https://bluearchive.wiki/wiki/Code:_BOX_Shadow_Looming_Over_Millennium_%EF%BD%9EOne_Question_and_Two_Answers%EF%BD%9E/Rerun",
+    "sourceId": "ba-bawiki-events",
+    "status": "published",
+    "confidence": 0.85,
+    "extractionMethod": "parser",
+    "version": 1,
+    "firstSeenAt": "2026-08-14T00:00:00.000Z",
+    "updatedAt": "2026-08-14T00:00:00.000Z"
+  },
+  {
+    "id": "ba:special-mission-lore-pursuit:2026-08-18",
+    "game": "ba",
+    "title": "Special Mission: Lore Pursuit",
+    "type": "other",
+    "summary": null,
+    "startsAt": "2026-08-18T00:00:00.000Z",
+    "startPrecision": "day",
+    "endsAt": "2026-09-01T00:00:00.000Z",
+    "endPrecision": "day",
+    "regionScoped": false,
+    "regionEnds": null,
+    "sourceUrl": "https://bluearchive.wiki/wiki/Special_Operation:_Lore_Pursuit",
+    "sourceId": "ba-bawiki-events",
+    "status": "published",
+    "confidence": 0.85,
+    "extractionMethod": "parser",
+    "version": 1,
+    "firstSeenAt": "2026-08-14T00:00:00.000Z",
+    "updatedAt": "2026-08-14T00:00:00.000Z"
+  },
+  {
+    "id": "ba:pray-ball-swing-for-the-grand-slam:2026-09-01",
+    "game": "ba",
+    "title": "Pray-Ball! Swing for the Grand Slam!",
+    "type": "rerun",
+    "summary": "Rerun",
+    "startsAt": "2026-09-01T00:00:00.000Z",
+    "startPrecision": "day",
+    "endsAt": "2026-09-15T00:00:00.000Z",
+    "endPrecision": "day",
+    "regionScoped": false,
+    "regionEnds": null,
+    "sourceUrl": "https://bluearchive.wiki/wiki/Pray-Ball!_%EF%BD%9E_Aim_for_a_Grand_Slam_Home_Run_%EF%BD%9E/Rerun",
+    "sourceId": "ba-bawiki-events",
+    "status": "published",
+    "confidence": 0.85,
+    "extractionMethod": "parser",
+    "version": 1,
+    "firstSeenAt": "2026-08-14T00:00:00.000Z",
+    "updatedAt": "2026-08-14T00:00:00.000Z"
+  },
+  {
+    "id": "ba:from-opera-0068-with-love:2026-09-15",
+    "game": "ba",
+    "title": "From Opera 0068 with Love!",
+    "type": "other",
+    "summary": null,
+    "startsAt": "2026-09-15T00:00:00.000Z",
+    "startPrecision": "day",
+    "endsAt": null,
+    "endPrecision": "unknown",
+    "regionScoped": false,
+    "regionEnds": null,
+    "sourceUrl": "https://bluearchive.wiki/wiki/0068_from_Opera_with_Love!/Permanent",
+    "sourceId": "ba-bawiki-events",
+    "status": "published",
+    "confidence": 0.75,
+    "extractionMethod": "parser",
+    "version": 1,
+    "firstSeenAt": "2026-08-14T00:00:00.000Z",
+    "updatedAt": "2026-08-14T00:00:00.000Z"
+  },
+  {
+    "id": "ba:special-mission-lore-pursuit:2026-09-15",
+    "game": "ba",
+    "title": "Special Mission: Lore Pursuit",
+    "type": "other",
+    "summary": "Season 2",
+    "startsAt": "2026-09-15T00:00:00.000Z",
+    "startPrecision": "day",
+    "endsAt": "2026-09-29T00:00:00.000Z",
+    "endPrecision": "day",
+    "regionScoped": false,
+    "regionEnds": null,
+    "sourceUrl": "https://bluearchive.wiki/wiki/Special_Operation:_Lore_Pursuit_(Season_2)",
+    "sourceId": "ba-bawiki-events",
+    "status": "published",
+    "confidence": 0.85,
+    "extractionMethod": "parser",
+    "version": 1,
+    "firstSeenAt": "2026-08-14T00:00:00.000Z",
+    "updatedAt": "2026-08-14T00:00:00.000Z"
+  }
+]