Confirmed against prod: exactly one track (17 plays, cold since May 21)
met the c>=5 + 30d-cold bar, and three process defects turned that into
a 1-track playlist instead of the locked placeholder.
- ListRediscoverTracks: collapse the two-tier UNION into one blended
pool. The old shallow-tier gate (WHERE NOT EXISTS deep) was
all-or-nothing — one 6-month row suppressed the entire 30-day tier —
and deep was a strict subset of shallow anyway. Eligibility drops to
>=3 non-skip plays (on a weeks-old history the >=5-play tracks are
precisely the ones still in rotation); ordering prefers >=6mo cold,
then >=5 plays, then raw count.
- Minimum viable mix floor for all five discovery mixes: below
minLen (15; 5 for the album-coherent NewForYou/FirstListens) the
variant is withheld so Home renders the 'listen more to unlock'
placeholder instead of a mix that reads as built-wrong.
- /api/events: clamp client-supplied 'at' to [user.created_at,
now+5m]. Unbounded client clocks could write arbitrarily old plays
and poison the 6-month ordering (prod data verified clean — no
scrub needed).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TsF3cNoKrqCYsU78cXC8U6
bvandeusen
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