Rust (2A):
- metadata: deezer_track_uncached (fresh mint, cache-updating, paced) and
fetch_preview_media — dedicated client whose custom redirect policy
re-validates every hop against the media allowlist; bounded body read
(cap enforced on received bytes, not Content-Length's promise); Date
header captured for provider-clock lease math. httpdate dep added.
- src-tauri/preview.rs: second Player instance + soulstream:preview event
channel; preview_resolve (fresh mint → host gate → MIME gate → ID3v2
shell strip → MPEG sync check → clip file + opaque lease id → safe_for_ms
mirroring lease.js); preview_load with start_paused via the
desired-paused latch; preview_control/dispose; player_pause_acked
exposing the Phase 0.4 ack on the MAIN player. 9 unit tests.
JS (2B):
- api.js: preview command surface (opaque lease ids only).
- nativeTransport.js: stamps {sessionId, generation, sessionKey} onto
backend events; cleared context makes stragglers dispatch nothing.
- productionResolver.js: DTO → MediaLease, failure classes preserved.
- focusBridge.js: production coordinator binding with the documented
renderer-side generation invariant (buffering counter + gateway).
- service.js: the orchestrator — settle window, resolve→load→play under
focus, single capped retry, one forward lease prefetch with safe-window
expiry, stale re-checks before every transport command, close/handoff.
The service constructs its transport around its own dispatch — the
factory signature exists because a pre-built transport silently loses
the event wiring (caught by test).
70 JS tests passing (npm test); metadata 46 + app preview 9 in cargo.
src/lib/preview/ — framework-free ESM modules, per design §12–14:
- contracts.js: versioned manifest/item/source-ref factories; signed
URLs structurally excluded from manifests; Apple identity first-class.
- lease.js: discriminated MediaLease union; computeSafeForMs derives
lifetimes provider-clock-first with fallback/contradiction handling
(margins are ADRs backed by Phase 0 soak evidence).
- redact.js: URL redaction (host+hash+exp only) and the HTTPS + exact
host allowlist gate applied to initial URLs and every redirect.
- manifest.js: artist (rank order, exact-id dedupe), album (disc/track
sort, context inheritance) and fixture builders — pure, no fetching.
- session.js: reducer with session/generation guards on every async
action; keyed active item with derived playable indices/cursor;
auto-advance under fresh generations; close is terminal.
- resolver.js: PreviewResolver contract + scripted fixture resolver
with classified failures (stale_lease/not_found/network/…).
- transport.js: transport seam + deterministic fake (manual ticks).
- focus.js: revision gateway (all main-player entry points; focus-
internal tag) and the coordinator — acquisition only via a
generation-bound silence ack, restore only with revisions unchanged.
tests/preview/*.test.mjs run via `npm test` (node --test): 61 passing,
covering the full Phase 1 list in IMPLEMENTATION-PLAN §6 including the
exit gate: stale lease/play events are inert, no restoration after any
simulated main command, and no component renders anywhere.
KeelrLeek