Add full-agency discovery exercise example

Demonstrates 8 agents (Product Trend Researcher, Backend Architect,
Brand Guardian, Growth Hacker, Support Responder, UX Researcher,
Project Shepherd, XR Interface Architect) deployed in parallel to
evaluate a software opportunity and produce a unified product plan.

Adds examples/ directory with README and the Nexus Spatial discovery
document. Links from the project README under a new Scenario 4 and
checks off the multi-agent workflow examples roadmap item.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

README.md

@@ -210,6 +210,16 @@ The unique specialists who don't fit in a box.
 
 ---
 
+### Scenario 4: Full Agency Product Discovery
+
+**Your Team**: All 8 divisions working in parallel on a single mission.
+
+See the **[Nexus Spatial Discovery Exercise](examples/nexus-spatial-discovery.md)** -- a complete example where 8 agents (Product Trend Researcher, Backend Architect, Brand Guardian, Growth Hacker, Support Responder, UX Researcher, Project Shepherd, and XR Interface Architect) were deployed simultaneously to evaluate a software opportunity and produce a unified product plan covering market validation, technical architecture, brand strategy, go-to-market, support systems, UX research, project execution, and spatial UI design.
+
+**Result**: Comprehensive, cross-functional product blueprint produced in a single session. [More examples](examples/).
+
+---
+
 ## 🤝 Contributing
 
 We welcome contributions! Here's how you can help:
@@ -302,7 +312,7 @@ Each agent is designed with:
 ## 🗺️ Roadmap
 
 - [ ] Interactive agent selector web tool
-- [ ] Multi-agent workflow examples
+- [x] Multi-agent workflow examples — see [examples/](examples/)
 - [ ] Video tutorials on agent design
 - [ ] Community agent marketplace
 - [ ] Agent "personality quiz" for project matching