docs(agentcore): add Cloud API URL to quickstart and config default

hindsight-docs/docs-integrations/agentcore.md

@@ -40,6 +40,10 @@ pip install hindsight-agentcore
 
 ## Quick Start
 
+:::tip Recommended: Hindsight Cloud
+[Sign up free](https://ui.hindsight.vectorize.io/signup) and grab an API key — no self-hosting required.
+:::
+
 ```python
 import os
 from hindsight_agentcore import HindsightRuntimeAdapter, TurnContext, configure

hindsight-docs/guides/2026-05-04-guide-agentcore-memory-with-hindsight.md

@@ -44,6 +44,8 @@ pip install hindsight-agentcore
 
 ## Step 2: Connect AgentCore Runtime to Hindsight
 
+> ✨ **Recommended:** [Hindsight Cloud](https://ui.hindsight.vectorize.io/signup) — free tier, no self-hosting required.
+
 ```python
 import os
 from hindsight_agentcore import configure
@@ -54,6 +56,8 @@ configure(
 )
 ```
 
+If you'd rather self-host on AWS (ECS/EKS with RDS PostgreSQL + pgvector), set `hindsight_api_url` to your in-VPC Hindsight endpoint.
+
 ## Step 3: Wire memory into your runtime
 
 ```python

hindsight-integrations/agentcore/README.md

@@ -34,6 +34,8 @@ pip install hindsight-agentcore
 
 ## Quick Start
 
+> ✨ **Recommended: [Hindsight Cloud](https://ui.hindsight.vectorize.io/signup)** — free tier, no self-hosting required. Sign up and grab an API key in under a minute.
+
 ```python
 import os
 from hindsight_agentcore import HindsightRuntimeAdapter, TurnContext, configure