Per bead bf-3e60: instead of copying B2->R2 (warm cache), bundle warm-set
replays, thumbnails, cards, and evolution live.json directly into the Pages
deploy directory as static assets (dist/data/). This serves replays same-origin,
eliminating R2 dependency and 404 errors.
Changes:
- Add B2Client interface for testable B2 operations
- Add bundleWarmReplays(): copies replays/*.json.gz from B2 to dist/data/replays/
- Add bundleWarmThumbnails(): copies thumbnails/*.png from B2 to dist/data/thumbnails/
- Add bundleWarmCards(): copies cards/*.png from B2 to dist/data/cards/
- Add bundleEvolutionLive(): copies evolution/live.json from B2 to dist/data/evolution/
- Replace promoteRecentReplaysForCycle() with bundleWarmAssetsForCycle()
- Remove R2 pruning logic from main loop (no longer needed)
- Add unit tests for all bundling functions with mock B2 client
Replays are served gzipped (as-is from B2) to keep deploy size under Pages'
25MB file limit. Frontend will gunzip client-side (separate bead bf-5cwi).
All tests pass (go test ./...).
Closes: bf-3e60
4b7d81db45