06-workshops - [Bug] 07-FGAC: Semantic search test case missing but referenced in README

**In which component is this bug present?**

- [ ] 01-AgentCore-runtime
- [x] 02-AgentCore-gateway
- [ ] 03-AgentCore-identity
- [ ] 04-AgentCore-memory
- [ ] 05-AgentCore-tools
- [ ] 06-AgentCore-observability
- [ ] 07-AgentCore-E2E

**Bug Description**

In the FGAC section (07-Centralise and govern your AI infrastructure), the README documents three access control patterns:
1. Invoke tool with FGAC (REQUEST interceptor) — block tools/call if the user's token doesn't include the required tool scope
2. Semantic search with FGAC (RESPONSE interceptor) — filter search results so users only see tools they have access to
3. List tools with FGAC (RESPONSE interceptor) — filter tools/list responses based on scopes

However, the test cases only implement patterns 1 and 3. Pattern 2 (Semantic search with FGAC) has no test case, and the interceptor Lambda would also need to be updated to support it.

**Expected Behavior**
All three documented patterns should have working test cases.

**Suggested Fix**
Add a test case for semantic search with FGAC and update the interceptor Lambda to handle RESPONSE filtering for search results.