release(v4.5.0): browser-side encrypted storage + multi-factor unlock

Adds the foundations Prism's web client (and any future browser-based
Shade app) needs: at-rest-encrypted IndexedDB storage that mirrors the
SQLite backend byte-for-byte at the AAD/nonce level, browser-safe
subpath imports so Vite/webpack/esbuild stop hitting bun:sqlite, and
KeyManager support for argon2id and N-factor composite unlock.

@shade/storage-encrypted
- EncryptedIndexedDBStorage (subpath: /idb) — full StorageProvider
  using one object store per _enc table; reuses aeadSeal/aeadOpen +
  row-codec sealers so a row sealed under the SQLite or Postgres
  backend decrypts under IDB given the same KeyManager.
  bumpPeerIdentityVersion is atomic under one IDB transaction.
- KeyManager argon2id source — memory-hard KDF for low-entropy
  secrets (PINs). Backed by @noble/hashes/argon2 (already a transitive
  dep). DEFAULT_ARGON2ID exported (m=64 MiB, t=3, p=1).
- KeyManager composite source — HKDF-combine N sub-sources into one
  master. Every source mandatory; order significant by design;
  composite-of-composite rejected; optional info string for app-level
  domain separation.
- Subpath exports (/crypto, /sqlite, /postgres, /idb) plus a `browser`
  condition on the default import that resolves to a barrel
  excluding the Bun- and Postgres-specific entries. Browser bundles
  no longer pull bun:sqlite transitively.

Tests
- 73 tests in shade-storage-encrypted (was 31). New coverage:
  argon2id determinism + reject paths, composite same-factors → same
  master, wrong-PIN/passphrase/order-swap → different master, info
  domain separation, all 28 StorageProvider methods on
  EncryptedIndexedDBStorage, fingerprint-mismatch rejection, and
  cross-impl roundtrip with EncryptedSQLiteStorage proving the AAD/
  nonce derivation is implementation-agnostic.

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

packages/shade-storage-encrypted/src/crypto.ts

@@ -0,0 +1,64 @@
+/**
+ * Browser-safe entry point — exports KeyManager + crypto primitives only.
+ *
+ * Use this subpath when bundling for the browser to avoid pulling
+ * `bun:sqlite` (Bun-only) or `postgres` (Node-only) into the output.
+ *
+ * ```ts
+ * import { KeyManager } from '@shade/storage-encrypted/crypto';
+ * ```
+ *
+ * For backend storage, import `@shade/storage-encrypted/sqlite` (Bun) or
+ * `@shade/storage-encrypted/postgres` (Node). For browser storage, import
+ * `@shade/storage-encrypted/idb`.
+ */
+
+export {
+  KeyManager,
+  type KeySource,
+  type KeychainBackend,
+  type KeyManagerOptions,
+} from './crypto/key-manager.js';
+export {
+  DEFAULT_SCRYPT,
+  DEFAULT_ARGON2ID,
+  type ScryptParams,
+  type Argon2idParams,
+  deriveMasterKey,
+  deriveMasterKeyArgon2id,
+  deriveStorageKey,
+  deriveFieldKey,
+  deriveNonce,
+  buildAad,
+  hkdfDerive,
+} from './crypto/kdf.js';
+export {
+  AEAD_NONCE_LEN,
+  AEAD_TAG_LEN,
+  aeadSeal,
+  aeadOpen,
+} from './crypto/aead.js';
+export {
+  COL,
+  TBL,
+  sealString,
+  openString,
+  sealBytes,
+  openBytes,
+  sealIdentity,
+  openIdentity,
+  sealConfig,
+  openConfig,
+  sealSignedPreKey,
+  openSignedPreKey,
+  sealOneTimePreKey,
+  openOneTimePreKey,
+  sealSession,
+  openSession,
+  sealTrust,
+  openTrust,
+  sealRetired,
+  openRetired,
+  sealStreamSensitive,
+  openStreamSensitive,
+} from './crypto/row-codec.js';