Add genshin-impact.fandom.com as a second source for Genshin Impact,
which has been fixture-backed in CI because Game8 CloudFront-blocks the
Actions runner with 202s.
- Add fifth Fandom template parser in src/ingest/parsers/fandom.ts
extracting titles from caption display text, stripping dated subpage
suffixes, and checking currency via latestBoundaryMs.
- Register genshin-fandom-events in src/ingest/adapters/index.ts and
set genshin-game8-events priority: 10 so existing event IDs survive
near-match ties, preventing localStorage completion marks from
orphaning.
- Explicitly sort adapter groups by priority descending in
scripts/build-feed.ts to align with parseGame.
- Pin fixtures and add test coverage in test/adapters/game8.test.ts.
- Update AGENTS.md, README.md, docs/INGESTION.md, and docs/SOURCES.md.
