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-inbox-server/src/events.ts

@@ -0,0 +1,90 @@
+/**
+ * Inbox server event emitter.
+ *
+ * Mirrors `PrekeyServerEvents`. Emits structural facts only — no plaintext,
+ * no signatures, no key material. Used by the observer dashboard and
+ * operator metrics.
+ */
+
+export interface InboxServerEventBase {
+  seq: number;
+  timestamp: number;
+}
+
+export interface InboxServerEventMap {
+  'inbox.address_registered': { address: string; signingKeyHash: string };
+  'inbox.address_deleted': { address: string };
+  'inbox.blob_stored': { address: string; msgId: string; bytes: number; ttlSeconds: number };
+  'inbox.blob_idempotent_replay': { address: string; msgId: string };
+  'inbox.blob_fetched': { address: string; count: number; bytes: number };
+  'inbox.blob_acked': { address: string; msgId: string };
+  'inbox.expired_purged': { count: number };
+  'inbox.rate_limited': { route: string; key: string };
+  'inbox.quota_rejected': { address: string; reason: 'address-quota' | 'sender-quota' | 'body-too-large' };
+}
+
+export type InboxServerEventName = keyof InboxServerEventMap;
+
+export type InboxServerEvent = {
+  [K in InboxServerEventName]: InboxServerEventBase & { name: K; data: InboxServerEventMap[K] };
+}[InboxServerEventName];
+
+export type InboxServerEventListener = (event: InboxServerEvent) => void;
+
+export class InboxServerEvents {
+  private listeners = new Set<InboxServerEventListener>();
+  private nextSeq = 1;
+  private buffer: InboxServerEvent[] = [];
+  private readonly maxBuffer: number;
+
+  constructor(options: { bufferSize?: number } = {}) {
+    this.maxBuffer = options.bufferSize ?? 1000;
+  }
+
+  on(listener: InboxServerEventListener): () => void {
+    this.listeners.add(listener);
+    return () => this.listeners.delete(listener);
+  }
+
+  off(listener: InboxServerEventListener): void {
+    this.listeners.delete(listener);
+  }
+
+  emit<K extends InboxServerEventName>(name: K, data: InboxServerEventMap[K]): void {
+    const event = {
+      seq: this.nextSeq++,
+      timestamp: Date.now(),
+      name,
+      data,
+    } as InboxServerEvent;
+
+    this.buffer.push(event);
+    if (this.buffer.length > this.maxBuffer) this.buffer.shift();
+
+    for (const listener of this.listeners) {
+      try {
+        listener(event);
+      } catch (err) {
+        console.error('[Shade] Inbox event listener threw:', err);
+      }
+    }
+  }
+
+  getBufferedSince(since: number): InboxServerEvent[] {
+    return this.buffer.filter((e) => e.seq > since);
+  }
+
+  getRecent(n: number): InboxServerEvent[] {
+    return this.buffer.slice(-n);
+  }
+
+  get currentSeq(): number {
+    return this.nextSeq - 1;
+  }
+}
+
+export async function shortHash(key: Uint8Array): Promise<string> {
+  const buf = await globalThis.crypto.subtle.digest('SHA-256', key as unknown as ArrayBuffer);
+  const arr = new Uint8Array(buf).slice(0, 8);
+  return Array.from(arr, (b) => b.toString(16).padStart(2, '0')).join('');
+}