docs: add Bob's Brain production ADK reference to community showcase

docs/guide/community-showcase.md

@@ -28,6 +28,24 @@ An intelligent learning platform that adapts to individual learning styles and p
 
 An AI-powered production monitoring assistant built for the Agentic Era Hackathon. This agent helps DevOps teams monitor system health, detect anomalies, and provide intelligent insights for maintaining production environments.
 
+### Bob's Brain
+**Repository:** [jeremylongshore/bobs-brain](https://github.com/jeremylongshore/bobs-brain)
+
+A production-grade multi-agent system built entirely with Google's Agent Development Kit (ADK) and Vertex AI Agent Engine. Bob's Brain demonstrates advanced ADK patterns including agent-to-agent (A2A) protocol, comprehensive CI/CD with ARV gates, and Terraform-first infrastructure.
+
+**Key Features:**
+- **Multi-Agent Architecture:** Orchestrator (bob) + foreman (iam-senior-adk-devops-lead) + 8 specialist agents
+- **A2A Protocol:** Full AgentCard implementation with foreman-worker pattern
+- **Hard Mode Rules:** R1-R8 compliance enforcement (ADK-only, drift detection, WIF authentication)
+- **CI/CD Excellence:** 8 GitHub Actions workflows with ARV validation gates and multi-stage approvals
+- **Documentation:** 141 organized docs including 20+ canonical standards (6767-series) reusable across repos
+- **Production Patterns:** Inline source deployment, smoke testing, comprehensive error handling
+
+**Technologies:** ADK, Vertex AI Agent Engine, Cloud Run, Terraform, GitHub Actions (WIF), Firestore
+**Deployment:** Agent Engine (inline source) + Cloud Run (A2A gateways + Slack webhook)
+
+This project serves as a reference implementation for production-grade ADK agent departments with enterprise CI/CD practices.
+
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 *This section will be updated regularly as we review and feature outstanding community submissions.*