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-webrtc/tests/connection.test.ts

@@ -0,0 +1,223 @@
+import { afterEach, describe, expect, it } from 'bun:test';
+import {
+  encodeChunkFrame,
+  encodeResumeQueryFrame,
+  randomRequestId,
+  STREAM_ID_LEN,
+  WIRE_CHUNK,
+  WIRE_CHUNK_ACK,
+  WIRE_RESUME_QUERY,
+  WIRE_RESUME_STATE,
+  WIRE_ERROR,
+  bytesEqual,
+} from '../src/wire.js';
+import { MemoryRtcFactory } from '../src/memory-rtc.js';
+import { MemoryShadeBridge, WebRtcSignalingChannel } from '../src/signaling.js';
+import { WebRtcConnectionManager } from '../src/manager.js';
+
+afterEach(() => {
+  MemoryRtcFactory.reset();
+});
+
+async function setupPair(opts?: {
+  bobReceiver?: import('../src/connection.js').WebRtcReceiverHooks;
+  aliceReceiver?: import('../src/connection.js').WebRtcReceiverHooks;
+}): Promise<{
+  alice: WebRtcConnectionManager;
+  bob: WebRtcConnectionManager;
+  aliceSig: WebRtcSignalingChannel;
+  bobSig: WebRtcSignalingChannel;
+}> {
+  const { a, b } = MemoryShadeBridge.linked('alice', 'bob');
+  const aliceSig = new WebRtcSignalingChannel(a);
+  const bobSig = new WebRtcSignalingChannel(b);
+  const factory = new MemoryRtcFactory();
+  const alice = new WebRtcConnectionManager({
+    factory,
+    signaling: aliceSig,
+    ...(opts?.aliceReceiver !== undefined ? { receiver: opts.aliceReceiver } : {}),
+  });
+  const bob = new WebRtcConnectionManager({
+    factory,
+    signaling: bobSig,
+    ...(opts?.bobReceiver !== undefined ? { receiver: opts.bobReceiver } : {}),
+  });
+  return { alice, bob, aliceSig, bobSig };
+}
+
+describe('WebRtcConnection — caller/callee handshake', () => {
+  it('opens a data channel after offer/answer/ICE flow', async () => {
+    const { alice, bob } = await setupPair();
+    const conn = await alice.getOrCreate('bob');
+    expect(conn.state).toBe('connected');
+    expect(bob.isConnected('alice')).toBe(true);
+
+    // The peer connection on the bob side should also be open and reachable.
+    const bobConn = await bob.getOrCreate('alice');
+    expect(bobConn.state).toBe('connected');
+
+    alice.destroy();
+    bob.destroy();
+  });
+
+  it('routes a chunk request to the receiver hook and replies with chunk-ack', async () => {
+    const calls: Array<{
+      from: string;
+      streamId: string;
+      laneId: number;
+      seq: bigint;
+      bytes: number;
+    }> = [];
+    const { alice, bob } = await setupPair({
+      bobReceiver: {
+        async onChunk(from, streamId, laneId, seq, envelope) {
+          calls.push({ from, streamId, laneId, seq, bytes: envelope.length });
+          return { lastSeq: Number(seq), bytesReceived: envelope.length };
+        },
+        async onResumeQuery() {
+          return null;
+        },
+      },
+    });
+
+    const conn = await alice.getOrCreate('bob');
+    const requestId = randomRequestId();
+    const streamId = new Uint8Array(STREAM_ID_LEN).fill(0xaa);
+    const envelope = new Uint8Array(64);
+    for (let i = 0; i < envelope.length; i++) envelope[i] = i;
+
+    const frame = encodeChunkFrame({
+      type: WIRE_CHUNK,
+      requestId,
+      streamId,
+      laneId: 3,
+      seq: 7n,
+      envelope,
+    });
+    const response = await conn.request(frame, requestId);
+    expect(response.type).toBe(WIRE_CHUNK_ACK);
+    if (response.type === WIRE_CHUNK_ACK) {
+      expect(bytesEqual(response.requestId, requestId)).toBe(true);
+      expect(response.lastSeq).toBe(7);
+      expect(response.bytesReceived).toBe(64);
+    }
+    expect(calls).toHaveLength(1);
+    expect(calls[0]!.laneId).toBe(3);
+    expect(calls[0]!.seq).toBe(7n);
+    expect(calls[0]!.bytes).toBe(64);
+
+    alice.destroy();
+    bob.destroy();
+  });
+
+  it('returns error frame when receiver throws', async () => {
+    const { alice, bob } = await setupPair({
+      bobReceiver: {
+        async onChunk() {
+          throw new Error('nope');
+        },
+        async onResumeQuery() {
+          return null;
+        },
+      },
+    });
+
+    const conn = await alice.getOrCreate('bob');
+    const requestId = randomRequestId();
+    const streamId = new Uint8Array(STREAM_ID_LEN).fill(0x01);
+    const frame = encodeChunkFrame({
+      type: WIRE_CHUNK,
+      requestId,
+      streamId,
+      laneId: 0,
+      seq: 0n,
+      envelope: new Uint8Array(4),
+    });
+    const response = await conn.request(frame, requestId);
+    expect(response.type).toBe(WIRE_ERROR);
+    if (response.type === WIRE_ERROR) {
+      expect(response.json).toContain('nope');
+    }
+
+    alice.destroy();
+    bob.destroy();
+  });
+
+  it('handles resume-query with not-found → error frame', async () => {
+    const { alice, bob } = await setupPair({
+      bobReceiver: {
+        async onChunk() {
+          return { lastSeq: 0 };
+        },
+        async onResumeQuery() {
+          return null;
+        },
+      },
+    });
+    const conn = await alice.getOrCreate('bob');
+    const requestId = randomRequestId();
+    const streamId = new Uint8Array(STREAM_ID_LEN).fill(0x55);
+    const frame = encodeResumeQueryFrame({
+      type: WIRE_RESUME_QUERY,
+      requestId,
+      streamId,
+    });
+    const res = await conn.request(frame, requestId);
+    expect(res.type).toBe(WIRE_ERROR);
+    if (res.type === WIRE_ERROR) {
+      expect(res.json).toContain('not found');
+    }
+    alice.destroy();
+    bob.destroy();
+  });
+
+  it('handles resume-query that returns state → resume-state frame', async () => {
+    const { alice, bob } = await setupPair({
+      bobReceiver: {
+        async onChunk() {
+          return { lastSeq: 0 };
+        },
+        async onResumeQuery(_from, streamId) {
+          return { streamId, lanes: [{ laneId: 0, lastSeqAcked: 11 }] };
+        },
+      },
+    });
+    const conn = await alice.getOrCreate('bob');
+    const requestId = randomRequestId();
+    const streamId = new Uint8Array(STREAM_ID_LEN).fill(0x77);
+    const frame = encodeResumeQueryFrame({
+      type: WIRE_RESUME_QUERY,
+      requestId,
+      streamId,
+    });
+    const res = await conn.request(frame, requestId);
+    expect(res.type).toBe(WIRE_RESUME_STATE);
+    if (res.type === WIRE_RESUME_STATE) {
+      const parsed = JSON.parse(res.json) as { lanes: { laneId: number; lastSeqAcked: number }[] };
+      expect(parsed.lanes[0]!.lastSeqAcked).toBe(11);
+    }
+    alice.destroy();
+    bob.destroy();
+  });
+});
+
+describe('WebRtcConnectionManager pool', () => {
+  it('reuses one connection per peer', async () => {
+    const { alice, bob } = await setupPair();
+    const c1 = await alice.getOrCreate('bob');
+    const c2 = await alice.getOrCreate('bob');
+    expect(c1).toBe(c2);
+    alice.destroy();
+    bob.destroy();
+  });
+
+  it('removes the connection from the pool when it closes', async () => {
+    const { alice, bob } = await setupPair();
+    const conn = await alice.getOrCreate('bob');
+    expect(alice.isConnected('bob')).toBe(true);
+    await conn.close('test');
+    expect(alice.isConnected('bob')).toBe(false);
+    alice.destroy();
+    bob.destroy();
+  });
+});