Fix Claude subagent narration leaking into chat (#1807)

* fix(claude): keep subagent text out of parent transcript

Sidechain tool activity is folded into the parent Task/Agent row, but sidechain assistant text was still going through the top-level text assembler. That made the chat show subagent narration without its matching tool rows.

* test(claude): simplify subagent sidechain assertion

packages/server/package.json

@@ -63,7 +63,7 @@
   },
   "dependencies": {
     "@agentclientprotocol/sdk": "^0.17.1",
-    "@anthropic-ai/claude-agent-sdk": "^0.3.181",
+    "@anthropic-ai/claude-agent-sdk": "^0.3.195",
     "@anthropic-ai/sdk": "^0.104.2",
     "@getpaseo/client": "0.1.102-beta.1",
     "@getpaseo/highlight": "0.1.102-beta.1",