fix(docker): update to .NET 10 SDK for k3s deployment

- Update Dockerfile.api to use dotnet/sdk:10.0-alpine
- Update runtime to aspnet:10.0-alpine
- Add deploy-k3s.sh script for manual deployments

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

deploy/docker/Dockerfile.api

@@ -1,5 +1,5 @@
 # Backend API - Multi-stage optimized build
-FROM mcr.microsoft.com/dotnet/sdk:9.0-alpine AS build
+FROM mcr.microsoft.com/dotnet/sdk:10.0-alpine AS build
 WORKDIR /src
 
 # Copy csproj files first for layer caching
@@ -17,7 +17,7 @@ COPY src/backend/ .
 RUN dotnet publish Host/Host.csproj -c Release -o /app --no-restore
 
 # Runtime image
-FROM mcr.microsoft.com/dotnet/aspnet:9.0-alpine AS runtime
+FROM mcr.microsoft.com/dotnet/aspnet:10.0-alpine AS runtime
 WORKDIR /app
 COPY --from=build /app .
 

deploy/scripts/deploy-k3s.sh

@@ -0,0 +1,39 @@
+#!/bin/bash
+# Deploy script for k3s cluster
+# Run this on the k3s master node after pulling latest code
+
+set -e
+
+NAMESPACE="student-enrollment"
+PROJECT_DIR="/home/andres/student-enrollment"
+TAG=$(git -C "$PROJECT_DIR" rev-parse --short HEAD)
+
+echo "=== Deploying commit $TAG to k3s ==="
+
+cd "$PROJECT_DIR"
+git pull
+
+echo "=== Building API image ==="
+sudo docker build -t student-api:$TAG -f deploy/docker/Dockerfile.api .
+
+echo "=== Building Frontend image ==="
+sudo docker build -t student-frontend:$TAG -f deploy/docker/Dockerfile.frontend .
+
+echo "=== Importing images to k3s ==="
+sudo docker save student-api:$TAG | sudo k3s ctr images import -
+sudo docker save student-frontend:$TAG | sudo k3s ctr images import -
+
+echo "=== Updating deployments ==="
+sudo kubectl -n $NAMESPACE set image deployment/student-api api=student-api:$TAG
+sudo kubectl -n $NAMESPACE set image deployment/student-frontend frontend=student-frontend:$TAG
+
+echo "=== Waiting for rollout ==="
+sudo kubectl -n $NAMESPACE rollout status deployment/student-api --timeout=120s
+sudo kubectl -n $NAMESPACE rollout status deployment/student-frontend --timeout=60s
+
+echo "=== Health check ==="
+sleep 5
+API_POD=$(sudo kubectl -n $NAMESPACE get pods -l app=student-api -o jsonpath='{.items[0].metadata.name}')
+sudo kubectl -n $NAMESPACE exec $API_POD -- wget -q --spider http://localhost:5000/health
+
+echo "=== Deploy complete! Tag: $TAG ==="