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/storage-hkdf.json

@@ -0,0 +1,52 @@
+{
+  "version": 2,
+  "vectors": [
+    {
+      "description": "Storage HKDF: storageKey = HKDF(masterKey, salt=0, info=\"shade-storage-v1\", 32)",
+      "masterKey": "0102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f20",
+      "storageKey": "059a250e15aa02952ab977f441e217cfcd4a6d9be8b51cf93d001a90eeb6accc"
+    },
+    {
+      "description": "Storage HKDF: fieldKey = HKDF(storageKey, salt=0, info=\"shade-field-v1:{table}:{column}\", 32)",
+      "storageKey": "059a250e15aa02952ab977f441e217cfcd4a6d9be8b51cf93d001a90eeb6accc",
+      "fields": [
+        {
+          "table": "sessions",
+          "column": "session",
+          "fieldKey": "0d1a61a8208d5374cc925039d336aace2cca57e10776e0d8a3a873638d6dc592"
+        },
+        {
+          "table": "identity",
+          "column": "identity",
+          "fieldKey": "bad14e2d54916c687de89c06d2efbc7fedfd3e5d1cbd2075afebc3f14e7c8917"
+        },
+        {
+          "table": "trusted_identities",
+          "column": "trusted_identity",
+          "fieldKey": "8e32c2d3d74c70fb5108793e8449cb0a4a151d57f8302fb61448814188da139d"
+        }
+      ]
+    },
+    {
+      "description": "Storage HKDF: rowNonce = HKDF(rowKey, salt=0, info=\"shade-row-nonce-v1:{table}:{pk}\", 12)",
+      "rowKey": "cdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcd",
+      "nonces": [
+        {
+          "table": "sessions",
+          "pk": "alice",
+          "nonce": "f72f291a2d3cd0ba652b60c5"
+        },
+        {
+          "table": "sessions",
+          "pk": "bob",
+          "nonce": "0f8922ef1e99d0bf8ff74a9a"
+        },
+        {
+          "table": "identity",
+          "pk": "1",
+          "nonce": "8daf77c7b3fbaffc3ddcdb14"
+        }
+      ]
+    }
+  ]
+}