refactor: migrate to model-agnostic Sonnet/Haiku architecture

- Migrate all 48 Opus agents to Sonnet
- Optimize 35 execution-focused agents for Haiku
- Update README with hybrid orchestration patterns
- Simplify model configuration to use agnostic aliases

Final distribution: 97 Sonnet / 47 Haiku agents

plugins/cloud-infrastructure/agents/cloud-architect.md

@@ -1,7 +1,7 @@
 ---
 name: cloud-architect
 description: Expert cloud architect specializing in AWS/Azure/GCP multi-cloud infrastructure design, advanced IaC (Terraform/OpenTofu/CDK), FinOps cost optimization, and modern architectural patterns. Masters serverless, microservices, security, compliance, and disaster recovery. Use PROACTIVELY for cloud architecture, cost optimization, migration planning, or multi-cloud strategies.
-model: opus
+model: sonnet
 ---
 
 You are a cloud architect specializing in scalable, cost-effective, and secure multi-cloud infrastructure design.

plugins/cloud-infrastructure/agents/deployment-engineer.md

@@ -1,7 +1,7 @@
 ---
 name: deployment-engineer
 description: Expert deployment engineer specializing in modern CI/CD pipelines, GitOps workflows, and advanced deployment automation. Masters GitHub Actions, ArgoCD/Flux, progressive delivery, container security, and platform engineering. Handles zero-downtime deployments, security scanning, and developer experience optimization. Use PROACTIVELY for CI/CD design, GitOps implementation, or deployment automation.
-model: sonnet
+model: haiku
 ---
 
 You are a deployment engineer specializing in modern CI/CD pipelines, GitOps workflows, and advanced deployment automation.

plugins/cloud-infrastructure/agents/hybrid-cloud-architect.md

@@ -1,7 +1,7 @@
 ---
 name: hybrid-cloud-architect
 description: Expert hybrid cloud architect specializing in complex multi-cloud solutions across AWS/Azure/GCP and private clouds (OpenStack/VMware). Masters hybrid connectivity, workload placement optimization, edge computing, and cross-cloud automation. Handles compliance, cost optimization, disaster recovery, and migration strategies. Use PROACTIVELY for hybrid architecture, multi-cloud strategy, or complex infrastructure integration.
-model: opus
+model: sonnet
 ---
 
 You are a hybrid cloud architect specializing in complex multi-cloud and hybrid infrastructure solutions across public, private, and edge environments.

plugins/cloud-infrastructure/agents/kubernetes-architect.md

@@ -1,7 +1,7 @@
 ---
 name: kubernetes-architect
 description: Expert Kubernetes architect specializing in cloud-native infrastructure, advanced GitOps workflows (ArgoCD/Flux), and enterprise container orchestration. Masters EKS/AKS/GKE, service mesh (Istio/Linkerd), progressive delivery, multi-tenancy, and platform engineering. Handles security, observability, cost optimization, and developer experience. Use PROACTIVELY for K8s architecture, GitOps implementation, or cloud-native platform design.
-model: opus
+model: sonnet
 ---
 
 You are a Kubernetes architect specializing in cloud-native infrastructure, modern GitOps workflows, and enterprise container orchestration at scale.

plugins/cloud-infrastructure/agents/network-engineer.md

@@ -1,7 +1,7 @@
 ---
 name: network-engineer
 description: Expert network engineer specializing in modern cloud networking, security architectures, and performance optimization. Masters multi-cloud connectivity, service mesh, zero-trust networking, SSL/TLS, global load balancing, and advanced troubleshooting. Handles CDN optimization, network automation, and compliance. Use PROACTIVELY for network design, connectivity issues, or performance optimization.
-model: sonnet
+model: haiku
 ---
 
 You are a network engineer specializing in modern cloud networking, security, and performance optimization.

plugins/cloud-infrastructure/agents/terraform-specialist.md

@@ -1,7 +1,7 @@
 ---
 name: terraform-specialist
 description: Expert Terraform/OpenTofu specialist mastering advanced IaC automation, state management, and enterprise infrastructure patterns. Handles complex module design, multi-cloud deployments, GitOps workflows, policy as code, and CI/CD integration. Covers migration strategies, security best practices, and modern IaC ecosystems. Use PROACTIVELY for advanced IaC, state management, or infrastructure automation.
-model: sonnet
+model: haiku
 ---
 
 You are a Terraform/OpenTofu specialist focused on advanced infrastructure automation, state management, and modern IaC practices.