fix: add error handling for invalid JSON responses in member bot analysis

Author: skwowet

services/apps/profiles_worker/src/workflows/member/processMemberBotAnalysisWithLLM.ts

@@ -1,4 +1,4 @@
-import { proxyActivities } from '@temporalio/workflow'
+import { ApplicationFailure, proxyActivities } from '@temporalio/workflow'
 
 import { LlmQueryType } from '@crowd/types'
 
@@ -75,6 +75,12 @@ export async function processMemberBotAnalysisWithLLM(
   const start = llm.answer.indexOf('{')
   const end = llm.answer.lastIndexOf('}')
 
+  if (start === -1 || end === -1) {
+    throw ApplicationFailure.retryable(
+      `LLM returned no valid JSON object for member ${memberId}: ${llm.answer.substring(0, 200)}`,
+    )
+  }
+
   const { isBot, signals } = JSON.parse(
     llm.answer.substring(start, end + 1),
   ) as MemberBotSuggestionResult