Restructure project: Move AKS cluster to beispiel-k8s-cluster directory

Major improvements:
- Import existing Azure AKS cluster with aztfexport
- Optimize VM size from Standard_D4d_v4 to Standard_D2as_v6 (50% cost reduction)
- Configure availability zones to [1, 2]
- Add comprehensive monitoring setup:
  * New Log Analytics Workspace
  * OMS Agent integration
  * Data Collection Rule for Container Insights
  * Email alerts for CPU and Memory
- Refactor configuration:
  * Extract all values to variables.tf
  * Rename resources with meaningful names
  * Add detailed outputs.tf
- Add project documentation:
  * Comprehensive README.md
  * cluster-status-commands.md with useful Azure CLI commands
  * terraform.tfvars.example template
  * .gitignore for sensitive files

Infrastructure changes:
- Resource Group: trusted_ai_demo_rg (Germany West Central)
- AKS Cluster: trai_k8s_cluster (Kubernetes 1.33)
- Node Pool: 2-3 nodes with auto-scaling
- Network: VNet 10.0.0.0/16, Subnet 10.0.0.0/24
- Monitoring: Full Container Insights with alerts

Cost optimization: ~€75/month (down from ~€140/month)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

beispiel-terraform/beispiel-k8s-cluster/provider.tf

@@ -0,0 +1,10 @@
+provider "azurerm" {
+  features {
+  }
+  subscription_id                 = var.subscription_id
+  environment                     = "public"
+  use_msi                         = false
+  use_cli                         = true
+  use_oidc                        = false
+  resource_provider_registrations = "none"
+}