release(v4.0.0): Shade GA — V3.x consolidation + audit prep

V3.1 → V3.12 consolidated and tagged for the first GA release. Wire
format unchanged from 0.4.x — 4.0 peers interoperate with 0.4.x peers
byte-for-byte. The version bump is semantic: audit-cycle complete,
opt-in surface fully exposed, threat model refreshed for every new
surface.

Highlights:
- All 24 @shade/* packages bumped to 4.0.0 in lockstep.
- CHANGELOG 4.0.0 section is the canonical manifest of what landed.
- THREAT-MODEL extended (§10 fingerprint gates, §11 WebRTC P2P, §12
  Web-Worker boundary) + residual-risks table refreshed.
- OpenAPI now covers all 27 routes: prekey, transfer, KT, inbox,
  bridge, observer, /metrics, /healthz, /ready.
- MIGRATION 0.3.x → 4.0 documented + smoke-tested against
  shade migrate-storage on a real SQLite DB.
- docs/audit/REVIEW-BUNDLE.md + SCOPE.md ready for external reviewer.
- scripts/soak.ts harness for the GA-stable 2-week soak window.
- All V*.md plans archived under docs/archive/ with Status: Done.
- Voice/Video carved out into V5.0; 4.0 audit focuses on the frozen
  non-realtime stack.

Tests: TS 1000/1000 + Kotlin 11/11 cross-platform vectors green.
Docker: gt.zyon.no/stian/shade-prekey:4.0.0 builds and reports
  version 4.0.0 on /health.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/archive/V3.8.md

@@ -0,0 +1,117 @@
+# Shade V3.8 — Web Workers Crypto
+
+**Status:** Done
+**Effort:** M-L (3–6 uker)
+**Forrige:** V3.1
+**Adresserer:** V2.2 §4
+**Levert:** `0.4.0`
+**Konsumentdokumentasjon:** [`docs/web-workers.md`](../web-workers.md)
+
+---
+
+## Mål
+
+Store filer i nettleseren skal kunne krypteres / dekrypteres uten å blokkere
+hovedtråden eller sprenge RAM. Dedikert Worker kjører `@shade/crypto-web` +
+`@shade/streams`, koblet til `@shade/transfer` via `ReadableStream` /
+`WritableStream`.
+
+---
+
+## Scope
+
+### Inn
+
+- Ny entry: `@shade/crypto-web/worker` — dedikert Web Worker med
+  `WorkerCryptoProvider`.
+- Hovedtråd-proxy: `MainThreadCryptoProvider` som forwarder kall til Worker.
+- Stream-pipeline: `ReadableStream<Uint8Array>` → Worker (transferable
+  buffers) → `@shade/transfer`-chunk-PUTs.
+- Lifecycle: spawn-on-demand, idle-timeout, terminate-on-rotate.
+- Safari-aware chunk-sizing (Safari har lavere `postMessage`-kapasitet).
+
+### Ut
+
+- Service Workers (background sync) — egen vurdering.
+- SharedArrayBuffer (krever COOP/COEP-headers; valgfritt opt-in).
+
+---
+
+## Design
+
+### Provider-API (uendret for konsumenter)
+
+```ts
+const crypto = await createWorkerCryptoProvider({
+  workerUrl: '/shade-crypto.worker.js',
+});
+const shade = await createShade({ crypto, ... });
+```
+
+`WorkerCryptoProvider` implementerer samme `CryptoProvider`-interface som
+`SubtleCryptoProvider`. Kall serialiseres med transferable `ArrayBuffer` så
+minne ikke kopieres.
+
+### Stream-pipeline
+
+```ts
+file.stream()
+  .pipeThrough(shade.encryptStream(peer))           // worker
+  .pipeThrough(shade.transfer.outboundChunks())     // main → http
+  .pipeTo(transferSink());
+```
+
+Worker-siden av `encryptStream` bruker `MultiLaneSender`.
+
+---
+
+## Leveranser
+
+### Kode
+
+- `@shade/crypto-web` — ny `worker.ts` entrypoint.
+- `@shade/sdk` — `shade.encryptStream` / `decryptStream`.
+- Bundler-eksempel for Vite, Webpack og Rollup.
+
+### Tester
+
+- Unit: postMessage roundtrip med transferable buffer.
+- Integration: 100 MB fil i nettleser uten frame-drop > 16 ms (P99).
+- Safari: chunked `postMessage`-workaround.
+
+### Dokumentasjon
+
+- `docs/web-workers.md` — setup, bundler-kvirks, Safari-notater, COOP/COEP
+  for SharedArrayBuffer-modus.
+
+---
+
+## Akseptansekriterier
+
+- [x] 100 MB upload i Chrome uten å blokkere main thread > 16 ms i P99
+      (Performance Observer-måling — verifiseringsoppskrift i
+      [`docs/web-workers.md`](../web-workers.md#verifying-main-thread-budget)).
+- [x] Safari fungerer med default chunk-size (256 KiB postMessage budget,
+      langt under Safari's transferable-grense).
+- [x] Worker termineres innen 30 s etter siste bruk
+      (`idleTimeoutMs`, default `30_000`).
+
+---
+
+## Avhengigheter
+
+Ingen direkte. Kan kjøres parallelt med V3.2 / V3.4.
+
+---
+
+## Risiko
+
+- **Bundler-helvete.** Vite, Webpack og Rollup behandler Workers ulikt.
+  Mitiger ved publisert recipe + integration-tester per bundler.
+- **Safari postMessage-grenser.** Test tidlig.
+
+---
+
+## Migrasjon
+
+Opt-in. Default forblir `SubtleCryptoProvider`.