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>

test-vectors/wire-format.json

@@ -1,7 +1,9 @@
 {
+  "version": 2,
   "vectors": [
     {
       "description": "Wire format: RatchetMessage encoding (wire VERSION 0x02 — u32 length-prefixed)",
+      "kind": "ratchet",
       "message": {
         "dhPublicKey": "1111111111111111111111111111111111111111111111111111111111111111",
         "previousCounter": 42,
@@ -10,6 +12,44 @@
         "nonce": "333333333333333333333333"
       },
       "encoded": "02020000002011111111111111111111111111111111111111111111111111111111111111110000002a0000000700000010222222222222222222222222222222220000000c333333333333333333333333"
+    },
+    {
+      "description": "Wire format: PreKeyMessage with one-time prekey (wire 0x02 type 0x01)",
+      "kind": "prekey",
+      "message": {
+        "registrationId": 305419896,
+        "preKeyId": 99,
+        "signedPreKeyId": 1,
+        "ephemeralKey": "7777777777777777777777777777777777777777777777777777777777777777",
+        "identityDHKey": "8888888888888888888888888888888888888888888888888888888888888888",
+        "inner": {
+          "dhPublicKey": "4444444444444444444444444444444444444444444444444444444444444444",
+          "previousCounter": 0,
+          "counter": 0,
+          "ciphertext": "5555555555555555",
+          "nonce": "666666666666666666666666"
+        }
+      },
+      "encoded": "02011234567800000063000000010000002077777777777777777777777777777777777777777777777777777777777777770000002088888888888888888888888888888888888888888888888888888888888888880000004800000020444444444444444444444444444444444444444444444444444444444444444400000000000000000000000855555555555555550000000c666666666666666666666666"
+    },
+    {
+      "description": "Wire format: PreKeyMessage without one-time prekey (preKeyId=null encoded as 0xFFFFFFFF)",
+      "kind": "prekey",
+      "message": {
+        "registrationId": 1,
+        "preKeyId": null,
+        "signedPreKeyId": 1,
+        "ephemeralKey": "9999999999999999999999999999999999999999999999999999999999999999",
+        "identityDHKey": "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
+        "inner": {
+          "dhPublicKey": "4444444444444444444444444444444444444444444444444444444444444444",
+          "previousCounter": 0,
+          "counter": 0,
+          "ciphertext": "5555555555555555",
+          "nonce": "666666666666666666666666"
+        }
+      },
+      "encoded": "020100000001ffffffff0000000100000020999999999999999999999999999999999999999999999999999999999999999900000020aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa0000004800000020444444444444444444444444444444444444444444444444444444444444444400000000000000000000000855555555555555550000000c666666666666666666666666"
     }
   ]
 }