Upgrade to .NET 8 and fix Azure Container Services compatibility

[Copilot]

.NET 6 reached EOL in November 2024, breaking this demo app across ACI, AKS, and ACA. Additionally, .NET 8 container images default to port 8080 (non-root user) instead of 80, requiring coordinated updates across all deployment artifacts.

App & Docker

• net6.0 → net8.0 in .csproj
• Dockerfile base images updated to sdk:8.0 / aspnet:8.0; added ENV ASPNETCORE_HTTP_PORTS=8080, EXPOSE 8080

FROM mcr.microsoft.com/dotnet/sdk:8.0 AS build-env
...
FROM mcr.microsoft.com/dotnet/aspnet:8.0 AS runtime
ENV ASPNETCORE_HTTP_PORTS=8080
EXPOSE 8080

Kubernetes Manifests

• All containerPort: 80 → containerPort: 8080
• Services updated with targetPort: 8080 (external port 80 preserved)

GitHub Actions Workflows

• deploy_to_aca.yml / deploy_to_aci.yml: replaced references to non-existent IaC/aca.bicep / IaC/aci.bicep with correct paths (azd/aca/modules/aca.bicep, azd/aci/modules/aci.bicep); fixed double-slash; passed containerPort=8080
• deploy_to_aci.yml: fixed ACR template path (azd/aci/modules/acr.bicep → azd/acr/modules/acr.bicep)

Bicep Infrastructure

• ACR modules: added missing outputs (loginServer, name, adminUsername, adminPassword) using listCredentials(); updated API version to 2023-07-01
• ACA module: replaced broken listCredentials child resource with listCredentials() function call; updated API versions; default port 8080; fixed cpu string→decimal type
• ACI module: same credential fix; updated API version; default port 8080
• azd/aca/main.bicep + infra.bicep: rewrote — were incorrectly deploying ACI resources via non-existent container-instance.bicep; now correctly deploy Container Apps via aca.bicep
• azd/aks/main.bicep + infra.bicep: rewrote — were referencing non-existent container-registry.bicep / container-instance.bicep; now deploy ACR + AKS cluster via existing modules

[sonarqubecloud]

Quality Gate failed

Failed conditions
2 Security Hotspots

See analysis details on SonarQube Cloud