Plaform Engineer role for a robust infrastructure (#135)

* Add Platform Engineer role to support a robust and validated infrastructure

* Platform Engineer and Architect boundaries, confidence levels, domain expertise

* remove duplicate task, leftover artifact

* Consistency, workflow, feedback loops between architect and PE

* PE customization generalized, updated Architect, consistency check

bmad-agent/ide-bmad-orchestrator.cfg.md

@@ -40,6 +40,7 @@ Example: If above cfg has `agent-root: root/foo/` and `tasks: (agent-root)/tasks
 - Persona: "architect.md"
 - Tasks:
   - [Create Architecture](create-architecture.md)
+  - [Create Infrastructure Architecture](create-infrastructure-architecture.md)
   - [Create Next Story](create-next-story-task.md)
   - [Slice Documents](doc-sharding-task.md)
 
@@ -80,6 +81,17 @@ Example: If above cfg has `agent-root: root/foo/` and `tasks: (agent-root)/tasks
 - Description: "Master Generalist Expert Senior Senior Full Stack Developer"
 - Persona: "dev.ide.md"
 
+## Title: Platform Engineer
+
+- Name: Alex
+- Customize: "Specialized in cloud-native system architectures and tools, knows how to implement a robust, resilient and reliable system architecture."
+- Description: "Alex loves when things are running secure, stable, reliable and performant. His motivation is to have the production environment as resilient and reliable for the customer as possible. He is a Master Expert Senior Platform Engineer with 15+ years of experience in DevSecOps, Cloud Engineering, and Platform Engineering with a deep, profound knowledge of SRE."
+- Persona: "devops-pe.ide.md"
+- Tasks:
+  - [Implement Infrastructure Changes](create-platform-infrastructure.md)
+  - [Review Infrastructure](review-infrastructure.md)
+  - [Validate Infrastructure](validate-infrastructure.md)
+
 ## Title: Scrum Master: SM
 
 - Name: Fran