feat: Sprint 8 — TypeScript SDK with WASM crypto and browser demo

- WASM crypto bundle (175KB): 13 wasm_bindgen functions wrapping
  quicproquo-core's Ed25519 identity, X25519+ML-KEM-768 hybrid KEM,
  safety numbers, sealed sender, and message padding
- @quicproquo/client TypeScript SDK: QpqClient class with connect,
  health, resolveUser, createChannel, send/sendWithTTL, receive,
  deleteAccount; WebSocket transport with request/response correlation
  and reconnection; ergonomic crypto.ts wrapper over WASM functions
- Browser demo: vanilla HTML page with interactive crypto operations
  (identity gen, safety numbers, sign/verify, hybrid encrypt/decrypt,
  sealed sender, padding) and chat UI for server connectivity
- Offline mode: crypto operations work without server connection

TypeScript strict mode, 0 errors. WASM bundle size optimized (lto + opt-level=s).

sdks/typescript/package-lock.json

@@ -0,0 +1,29 @@
+{
+  "name": "@quicproquo/client",
+  "version": "0.1.0",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "@quicproquo/client",
+      "version": "0.1.0",
+      "devDependencies": {
+        "typescript": "^5.0.0"
+      }
+    },
+    "node_modules/typescript": {
+      "version": "5.9.3",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.9.3.tgz",
+      "integrity": "sha512-jl1vZzPDinLr9eUt3J/t7V6FgNEw9QjvBPdysz9KfQDD41fQrC2Y4vKQdiaUpFT4bXlb1RHhLpp8wtm6M5TgSw==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "bin": {
+        "tsc": "bin/tsc",
+        "tsserver": "bin/tsserver"
+      },
+      "engines": {
+        "node": ">=14.17"
+      }
+    }
+  }
+}