feat(sdk): P2.5 @insignia/iios-kernel-client — REST + socket facade

MessageSocket (open/send/read/typing via emitWithAck, reconnect re-opens thread,
no socket.io types leak) + RestClient (ingest/getThreadMessages/sendMessage).
tsup ESM+dts. Facade unit test with injectable fake socket (3 tests).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

packages/iios-kernel-client/tsconfig.json

@@ -0,0 +1,13 @@
+{
+  "extends": "../../tsconfig.base.json",
+  "compilerOptions": {
+    "outDir": "./dist",
+    "rootDir": "./src",
+    "module": "ESNext",
+    "moduleResolution": "bundler",
+    "lib": ["ES2022", "DOM"],
+    "types": []
+  },
+  "include": ["src/**/*.ts"],
+  "exclude": ["src/**/*.test.ts"]
+}