release(dsh): align master packages with 0.2.1-rc.4

packages/experimental/client-ui-stats/package.json

@@ -1,7 +1,7 @@
 {
   "name": "@deepseek-ai/dsh-experimental-client-ui-stats",
   "description": "Per-turn and per-step context, timing, cache, and tool-cost table contributed as an experimental conversation View",
-  "version": "0.2.1-rc.3",
+  "version": "0.2.1-rc.4",
   "publishConfig": {
     "access": "public"
   },