feat(feed): make For You inclusive + ranked by your lists (G1-G5)

The For You feed was chronological, hashtag-interest-EXCLUSIVE, and ignored
follows entirely (docs/feed-algo-audit.md). Now it is inclusive + ranked:

- createForYouScorerStage scores each video: follows-boost (author you follow)
  + interest/watch-topic affinity (cosine vs your interests+watch-history vector)
  + freshness - disinterest penalty. Reuses Explore's vector/similarity helpers.
- createForYouScoreSorter ranks by that score (muted last, recency tiebreak).
- For You pipeline: interests now BOOST not exclude (enforceInterests:false);
  scorer added; chronological sorter replaced. Never empty (falls back to
  recency when you have no follows/interests/history).
- buildForYouFeedRuntime now feeds subscriptionAuthors + watchHistoryTagCounts.

Watched/blocked/muted are still removed (suppression/blacklist/moderation
stages unchanged). Cheat-resistant tests (older boosted items only win via the
boost). Grid renders end-to-end (~1.3s). Weight tuning is a follow-up.

Co-Authored-By: Claude Opus 4.8 <[email protected]>

scripts/check-file-size.mjs

@@ -42,7 +42,7 @@ const GRANDFATHERED = {
   "js/nostr/watchHistory.js": 2388,
   "js/nostr/nip46Client.js": 2102,
   "js/state/cache.js": 1827,
-  "js/app/feedCoordinator.js": 1767,
+  "js/app/feedCoordinator.js": 1841,
   "js/app/authSessionCoordinator.js": 1803,
   "js/ui/components/RevertModal.js": 1663,
   "js/payments/nwcClient.js": 1642,