02-use-cases - [Content Improvement] Document memory namespace trailing slash convention

**Please list the sample in which the bug is present.**

```
02-use-cases/SRE-agent/
02-use-cases/cost-optimization-agent/
02-use-cases/customer-support-assistant/
02-use-cases/intelligent-event-agent/
02-use-cases/market-trends-agent/
02-use-cases/slide-deck-generator-memory-agent/
```

**Improvement Description**

We are using namespace with trailing slash as the standard convention, so we want to ensure all memory namespace examples consistently use trailing slashes for proper path parsing and prefix matching.