4 Commits

Include renames

Author	SHA1	Message	Date
bvandeusenandClaude Fable 5	9e02878b61	feat(playlists): For You composition v2 — multi-seed blend + weighted fresh tail ... Two approved composition changes (#1269), mechanism only — the taste/fresh share stays data-decided (#1252) and pick_kind attribution is unchanged. Multi-seed blending: each day's build now seeds from up to 3 of the user's top-5 tracks (pickDailySeeds, the generalized daily shuffle) instead of one rotating anchor, so the mix spans neighborhoods within a day and stops feeling bipolar as the rotation swings between dissimilar seeds. Per-seed pools merge first-seen-deduped; the head is filled best-first under 50/30/20 per-seed quotas (60/40 for two seeds) so one neighborhood can't monopolize it, with thin-seed quota spilling best-first. Score-weighted fresh tail: the tail sample (rank 2*headN onward) was uniform — the 380th-best candidate as likely as the 101st. It now uses deterministic Efraimidis-Spirakis keys with weight halving every 50 ranks, so freshness keeps its "you'll probably enjoy this" half while still rotating daily. The retired single-seed picker's one other caller, You-might-like, moves to pickDailySeeds(n=1) — a single neighborhood per day is right for a short shelf, and the behavior note is inline. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01TsF3cNoKrqCYsU78cXC8U6	2026-07-03 09:02:35 -04:00
bvandeusenandClaude Fable 5	fb4431207d	feat(recommendation): For You exploration attribution — taste vs fresh picks ... Milestone #127 step 2 (#1249). For You deliberately blends two populations — a head of top-scored taste picks and a tail sampled from deeper ranking (the freshness injection) — but the metrics judged it as one blob, so its skip rate couldn't distinguish "the taste engine is missing" from "the freshness tax is too high". That number decides the exploration share before we tune it. - Migration 0038: nullable pick_kind ('taste'|'fresh') on both playlist_tracks (stamped at snapshot build) and play_events (frozen at play-ingestion — the snapshot rebuilds daily, so attribution cannot be reconstructed at read time). - Builder: pickHeadAndTail marks head=taste / tail=fresh; the small-pool fallback is all taste (top-N-by-score IS the taste mechanism). Other variants persist NULL. - Ingestion: for_you plays (live + offline replay) look the track up in the user's current snapshot; not found → unattributed, never guessed. - Metrics: For You's row gains a breakdown (taste / fresh / earlier unattributed plays), parent row stays the sum; web card renders the sub-rows indented with the same baseline deltas + low-data dimming. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01TsF3cNoKrqCYsU78cXC8U6	2026-07-02 20:39:41 -04:00
bvandeusenandClaude Opus 4.7	5cd342d521	feat(playlists): daily seed rotation + jitter + 12+13 split for system playlists ... Five diversity mechanics — applied to both For-You and Songs-Like-X. 1. For-You seed rotates daily across the user's top-5 most-played tracks. pickForYouSeedForDay uses userIDHash(user, day) mod len(seeds) so today's mix uses an entirely different similarity pool than tomorrow's. Within-day determinism preserved. 2. JitterMagnitude bumped 0.0 → 0.1. The scoring RNG is now seeded by userIDHash(user, day) rather than the no-op, so near-tied candidates shuffle daily without breaking within-day stability. 3. Head/tail split moves from 20+5 to 12+13. Roughly half the playlist comes from the tail now (daily-deterministic via tieBreakHash), giving the user substantially different content while a 12-track anchor of strong similarity matches keeps the mix recognizable. 4. Songs-Like-X seed artists shuffle daily across the user's top-5 played artists. pickSeedArtistsForDay applies a userIDHash-seeded Fisher-Yates and takes 3. 5. scoreAndSortCandidates / pickTopN / pickHeadAndTail gain a userID parameter so the RNG can be seeded per-user; existing call sites updated; noopRNG removed. Test fixtures widened similarity gaps (e.g. float64(50-i) instead of (50-i)/50) so the new jitter (±0.1) doesn't perturb head ordering in assertions about the head/tail mechanism. New seed_selection_test coverage for userIDHash + pickForYouSeedForDay + pickSeedArtistsForDay spans deterministic-within-day, varies-across-days, and graceful degradation with small candidate pools. PickTopPlayedTrackForUser replaced by PickTopPlayedTracksForUser :many in the prior commit (b4801c2). The For-You seed lookup now goes through pickForYouSeedForDay over the returned slice. PickSeedArtists's LIMIT widened to 5 in the same prior commit. For #392 Half A — system playlist content diversity. Half B (per-user timezone scheduling) is a separate spec. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>	2026-05-13 10:19:49 -04:00
bvandeusenandClaude Sonnet 4.6	0bfd51a149	feat(server/playlists): For-You head+tail + diversity caps ... Two improvements to the system playlist builder: 1. Per-artist (<=3) and per-album (<=2) caps applied to the pickTopN truncation step, using the same numeric caps Discover already enforces. Both For-You and Songs-like-X benefit. Same skewed candidate pool no longer collapses to "10 tracks from the same artist" — the playlist always carries at least 9 distinct artists in 25 slots. 2. New pickHeadAndTail function for For-You: 20 top-similarity tracks + 5 sampled from the tail (positions 2*headN onward of the score-sorted, cap-applied pool). Tail sampling uses tieBreakHash for daily determinism — same user same day still sees the same playlist, but the daily refresh feels less stuck-in-a-rut. Tail tracks are still similarity-related (they passed the similarity candidate filter) so the user should enjoy them, just from artists they wouldn't have surfaced via strict top-N ranking. Songs-like-X keeps the simple pickTopN call — the seed-artist context already provides the "you'll like this" framing without needing a tail injection. Refactors pickTopN internals: now sorts candidates first via scoreAndSortCandidates, applies the cap on []Candidate via capCandidatesByAlbumAndArtist, and truncates. Removes the now- dead stableSortByScoreThenHash helper (only used in old pickTopN). The cap helper mirrors capByAlbumAndArtist in discover.go but operates on recommendation.Candidate so it sees Track.AlbumID / Track.ArtistID directly. Tests cover the cap helper truth table, head+tail split with small/large pools, buffer-zone exclusion, daily determinism, and cross-day tail variance. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>	2026-05-07 10:34:39 -04:00