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>

packages/shade-transport-bridge/README.md

@@ -0,0 +1,45 @@
+# @shade/transport-bridge
+
+Transport-agnostic delivery for Shade: **WS → SSE → long-poll**, in priority
+order, behind a single `IncomingMessage` interface.
+
+```ts
+import {
+  FallbackBridgeTransport,
+  WsBridge,
+  SseBridge,
+  LongPollBridge,
+} from '@shade/transport-bridge';
+
+const auth = { crypto, signingPrivateKey, address: 'bob' };
+
+const bridge = new FallbackBridgeTransport([
+  new WsBridge({       baseUrl, auth }),
+  new SseBridge({      baseUrl, auth }),
+  new LongPollBridge({ baseUrl, auth }),
+]);
+
+await bridge.connect({
+  onMessage: (msg) => {
+    // msg: { from: string; bytes: Uint8Array; receivedAt: number; msgId?: string }
+  },
+});
+
+console.log(bridge.activeKind); // "ws" | "sse" | "long-poll"
+```
+
+Pair with `createBridgeRoutes` in `@shade/inbox-server` to expose the
+matching `/v1/bridge/{stream,poll,ws}` endpoints. Full design + threat
+model in [`docs/transport.md`](../../docs/transport.md).
+
+## What it solves
+
+Browser extensions, strict corporate proxies, and edge runtimes routinely
+block long-lived WebSockets. Apps that already use the Shade inbox shouldn't
+have to write three custom delivery paths to handle the realistic mix of
+hostile networks they ship into. This package is the canonical answer.
+
+## Status
+
+V3.7. Stable wire format, additive change to `@shade/inbox-server`. See
+[CHANGELOG](../../CHANGELOG.md).