Add Docker support

Docker configuration:
- Dockerfile: Multi-stage build with non-root user, health checks
- Dockerfile.migrations: Runs EF Core migrations on startup
- docker-compose.yml: Full stack with SQL Server, Azurite, app
- .dockerignore: Optimized build context
- .env.example: Template for API keys

Application changes:
- Added /health endpoint with EF Core database check
- Conditional HTTPS redirect (disabled in containers)
- DOTNET_RUNNING_IN_CONTAINER environment detection

Usage:
  cp .env.example .env  # Add your API keys
  docker-compose up -d  # Start all services

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

docker-compose.yml

@@ -0,0 +1,88 @@
+version: '3.8'
+
+services:
+  # TrueCV Web Application
+  truecv-web:
+    build:
+      context: .
+      dockerfile: Dockerfile
+    container_name: truecv-web
+    ports:
+      - "5000:8080"
+    environment:
+      - ASPNETCORE_ENVIRONMENT=Development
+      - ConnectionStrings__DefaultConnection=Server=sqlserver;Database=TrueCV;User Id=sa;Password=TrueCV_P@ssw0rd!;TrustServerCertificate=True;
+      - ConnectionStrings__HangfireConnection=Server=sqlserver;Database=TrueCV_Hangfire;User Id=sa;Password=TrueCV_P@ssw0rd!;TrustServerCertificate=True;
+      - AzureBlob__ConnectionString=DefaultEndpointsProtocol=http;AccountName=devstoreaccount1;AccountKey=Eby8vdM02xNOcqFlqUwJPLlmEtlCDXJ1OUzFT50uSRZ6IFsuFq2UVErCz4I6tq/K1SZFPTOtr/KBHBeksoGMGw==;BlobEndpoint=http://azurite:10000/devstoreaccount1;
+      - AzureBlob__ContainerName=cv-uploads
+      - CompaniesHouse__BaseUrl=https://api.company-information.service.gov.uk
+      - CompaniesHouse__ApiKey=${COMPANIES_HOUSE_API_KEY:-}
+      - Anthropic__ApiKey=${ANTHROPIC_API_KEY:-}
+    depends_on:
+      sqlserver:
+        condition: service_healthy
+      azurite:
+        condition: service_started
+    networks:
+      - truecv-network
+    restart: unless-stopped
+
+  # SQL Server Database
+  sqlserver:
+    image: mcr.microsoft.com/mssql/server:2022-latest
+    container_name: truecv-sqlserver
+    ports:
+      - "1433:1433"
+    environment:
+      - ACCEPT_EULA=Y
+      - MSSQL_SA_PASSWORD=TrueCV_P@ssw0rd!
+      - MSSQL_PID=Developer
+    volumes:
+      - sqlserver-data:/var/opt/mssql
+    networks:
+      - truecv-network
+    healthcheck:
+      test: /opt/mssql-tools18/bin/sqlcmd -S localhost -U sa -P "TrueCV_P@ssw0rd!" -C -Q "SELECT 1" || exit 1
+      interval: 10s
+      timeout: 5s
+      retries: 10
+      start_period: 30s
+    restart: unless-stopped
+
+  # Azure Storage Emulator (Azurite)
+  azurite:
+    image: mcr.microsoft.com/azure-storage/azurite:latest
+    container_name: truecv-azurite
+    ports:
+      - "10000:10000"  # Blob service
+      - "10001:10001"  # Queue service
+      - "10002:10002"  # Table service
+    volumes:
+      - azurite-data:/data
+    command: "azurite --blobHost 0.0.0.0 --queueHost 0.0.0.0 --tableHost 0.0.0.0 --location /data --debug /data/debug.log"
+    networks:
+      - truecv-network
+    restart: unless-stopped
+
+  # Database initialization (runs migrations)
+  db-init:
+    build:
+      context: .
+      dockerfile: Dockerfile.migrations
+    container_name: truecv-db-init
+    environment:
+      - ConnectionStrings__DefaultConnection=Server=sqlserver;Database=TrueCV;User Id=sa;Password=TrueCV_P@ssw0rd!;TrustServerCertificate=True;
+    depends_on:
+      sqlserver:
+        condition: service_healthy
+    networks:
+      - truecv-network
+    restart: "no"
+
+networks:
+  truecv-network:
+    driver: bridge
+
+volumes:
+  sqlserver-data:
+  azurite-data: