release(v4.9.0): relay-side encrypted blob primitive + SDK Profile namespace

Ships the Prism FR (encrypted-profile-storage-v4.9.md) as a generic
relay-side encrypted blob primitive: deterministically-located,
AEAD-sealed blobs keyed by a 32-byte slotId derived client-side via
HKDF from the user's master key. Unlocks credential-only bootstrap
of new devices into existing E2EE state — no QR, no physical access.

Server: BlobStore interface + Memory/Sqlite/Postgres impls,
createBlobRoutes for GET/PUT/DELETE /v1/blob/:slotId with TOFU pubkey
auth and If-Match CAS (409/412 semantics). Mounted on the same Hono
app as the inbox; SHADE_BLOB_PG_URL / SHADE_BLOB_DB_PATH /
SHADE_DISABLE_BLOB env-var plumbing in standalone.

SDK: createProfileNamespace high-level wrapper (HKDF derivation,
random-nonce AEAD seal, slotId-bound AAD) + low-level BlobClient.
Cross-platform test vectors in test-vectors/blob-storage.json.

New errors: ConflictError (409), PreconditionFailedError (412).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/shade-inbox-server/src/memory-blob-store.ts

@@ -0,0 +1,85 @@
+import { ConflictError, PreconditionFailedError } from '@shade/core';
+import type { BlobStore, BlobSlotRecord, PutBlobResult } from './blob-store.js';
+
+/**
+ * In-memory BlobStore — used in tests and as the default fallback when
+ * no SQLite/Postgres URL is configured. Rows are kept in a single Map.
+ *
+ * Etag is a strictly-monotonic per-process counter — guarantees a total
+ * order across writes even when many land in the same millisecond. (We
+ * could scope it per-slot, but a global counter keeps the implementation
+ * trivial and the etag values still uniquely identify the write that
+ * produced them, which is all CAS needs.)
+ */
+export class MemoryBlobStore implements BlobStore {
+  private slots = new Map<string, BlobSlotRecord>();
+  private nextEtag = 0;
+
+  async get(slotId: string): Promise<BlobSlotRecord | null> {
+    const r = this.slots.get(slotId);
+    if (!r) return null;
+    return {
+      slotId: r.slotId,
+      blob: new Uint8Array(r.blob),
+      ownerPubkey: new Uint8Array(r.ownerPubkey),
+      etag: r.etag,
+      updatedAt: r.updatedAt,
+    };
+  }
+
+  async put(args: {
+    slotId: string;
+    blob: Uint8Array;
+    ownerPubkey: Uint8Array;
+    expectedEtag: number | '*' | undefined;
+    now: number;
+  }): Promise<PutBlobResult> {
+    const existing = this.slots.get(args.slotId);
+
+    if (!existing) {
+      // Empty slot. `ifMatch: '*'` per RFC 7232 still fails — there is
+      // no entity to match. A numeric etag also fails (we have nothing
+      // to compare against).
+      if (args.expectedEtag !== undefined) {
+        throw new PreconditionFailedError(
+          `Slot ${args.slotId} does not exist; cannot match ifMatch=${String(args.expectedEtag)}`,
+        );
+      }
+      this.nextEtag = Math.max(this.nextEtag + 1, args.now);
+      const etag = this.nextEtag;
+      this.slots.set(args.slotId, {
+        slotId: args.slotId,
+        blob: new Uint8Array(args.blob),
+        ownerPubkey: new Uint8Array(args.ownerPubkey),
+        etag,
+        updatedAt: args.now,
+      });
+      return { created: true, etag, updatedAt: args.now };
+    }
+
+    // Slot exists. Pubkey check is the route layer's job — by the time
+    // we're here the signature has already been verified against
+    // `existing.ownerPubkey`.
+    if (args.expectedEtag === undefined) {
+      throw new ConflictError(
+        `Slot ${args.slotId} already exists; supply ifMatch to update`,
+      );
+    }
+    if (args.expectedEtag !== '*' && args.expectedEtag !== existing.etag) {
+      throw new PreconditionFailedError(
+        `Slot ${args.slotId} etag mismatch: expected=${args.expectedEtag} actual=${existing.etag}`,
+      );
+    }
+
+    this.nextEtag = Math.max(this.nextEtag + 1, args.now);
+    const etag = this.nextEtag;
+    existing.blob = new Uint8Array(args.blob);
+    existing.etag = etag;
+    existing.updatedAt = args.now;
+    return { created: false, etag, updatedAt: args.now };
+  }
+
+  async delete(slotId: string): Promise<boolean> {
+    return this.slots.delete(slotId);
+  }
+}