Phase 1: preview contracts and pure session core, 61 tests

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.

package.json

@@ -2,11 +2,12 @@
   "name": "soulstream",
   "version": "0.1.0",
   "type": "module",
-  "description": "SoulStream — music player, downloader and streamer for the Soulseek network",
+  "description": "SoulStream \u2014 music player, downloader and streamer for the Soulseek network",
   "scripts": {
     "dev": "vite",
     "build": "vite build",
-    "tauri": "tauri"
+    "tauri": "tauri",
+    "test": "node --test tests/preview/*.test.mjs"
   },
   "license": "ISC",
   "devDependencies": {