Add libsodium-wrappers-sumo runtime dependency

The 'sumo' build is required for crypto_pwhash (Argon2id), which Ente
uses to derive the KEK from the user's password. Pinned to exact
versions in package.json with integrity hashes in yarn.lock per repo
policy on hash-pinned external references.

package.json

@@ -29,11 +29,15 @@
     },
     "devDependencies": {
         "@eslint/js": "9.38.0",
+        "@types/libsodium-wrappers-sumo": "0.8.2",
         "@types/node": "22.18.13",
         "eslint": "9.38.0",
         "prettier": "3.8.1",
         "typescript": "5.9.3",
         "typescript-eslint": "8.46.2",
         "vitest": "2.1.9"
+    },
+    "dependencies": {
+        "libsodium-wrappers-sumo": "0.8.4"
     }
 }