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/package.json

@@ -1,17 +1,31 @@
 {
   "name": "@shade/storage-encrypted",
-  "version": "4.4.0",
+  "version": "4.5.0",
   "type": "module",
   "main": "src/index.ts",
   "types": "src/index.ts",
+  "exports": {
+    ".": {
+      "browser": "./src/index.browser.ts",
+      "default": "./src/index.ts"
+    },
+    "./crypto": "./src/crypto.ts",
+    "./sqlite": "./src/sqlite.ts",
+    "./postgres": "./src/postgres.ts",
+    "./idb": "./src/idb.ts"
+  },
   "dependencies": {
     "@noble/hashes": "^2.0.1",
     "@shade/core": "workspace:*",
     "@shade/crypto-web": "workspace:*",
     "@shade/storage-postgres": "workspace:*",
     "@shade/storage-sqlite": "workspace:*",
+    "idb": "^8.0.3",
     "postgres": "^3.4.9"
   },
+  "devDependencies": {
+    "fake-indexeddb": "^6.0.0"
+  },
   "peerDependencies": {
     "@shade/keychain": "workspace:*"
   },