fix(web): show Stems & Downloads section for stem-only tracks

[dylanjeffers]

Problem

Reported in Slack: after purchasing a premium sample pack on web, the extras (downloadable files) never appear. Michael could see them on the native mobile app but not on web.

Repro track: Sounds For The People Vol. 2 | ATMO & TEXTURES

Root cause

This is not a post-purchase access-gate problem — the section never renders for this track regardless of purchase state.

The web track page gated the Stems & Downloads section on is_downloadable alone:

// GiantTrackTile.tsx
const shouldShowDownloadSection = !!track?.is_downloadable

Sample packs have is_downloadable === false — the purchased content is entirely stems. Confirmed against the reported track via the API:

is_downloadable   = false
is_download_gated = true
stem count        = 12

So the gate evaluated to false and the section was never mounted. Native mobile gates on is_downloadable || stems.length > 0, which is why it worked there.

The mobile-web TrackHeader looked correct (is_downloadable || (_stems?.length ?? 0) > 0), but _stems is a vestigial field on the Track model that nothing ever assigns — it's only ever read. That check silently degraded to the same broken condition.

Fix

Match native mobile's gate on both web surfaces by sourcing stems from the useStems query:

• GiantTrackTile.tsx (desktop) — add the stems check.
• TrackHeader.tsx (mobile web) — use useStems and drop the dead _stems read.

Verification

Ran the web client against production and loaded the reported track logged out, toggling the fix via git stash to isolate cause and effect:

• Before: no Stems & Downloads section at all.
• After: section renders and lists all 12 stems.

The purchase gate itself was already correct — once the section mounts, useDownloadableContentAccess drives the locked/unlocked state as expected.

tsc --noEmit and eslint pass clean on both changed files.

Notes for reviewers

• Adds a useStems query to the desktop track tile. It's the same query the DownloadSection already issues, so it's a cache hit rather than an extra request.
• _stems is now unread on the track page but still referenced by the purchase modals (PurchaseContentPage, GuestCheckoutPage, PremiumContentPurchaseDrawer, PurchaseSuccess), where it looks equally dead — those show a stem count in the purchase UI and are likely rendering 0. Left alone here to keep this fix scoped; worth a follow-up.

🤖 Generated with Claude Code

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