feat: Convert website from static HTML to .NET 9.0 Blazor Web App

Major architectural upgrade from static HTML site to modern Blazor Web App:

- Migrated to .NET 9.0 Blazor Web App framework
- Converted home page with 4 gateway cards (Help Desk, App Store, Cloud, SDK)
- Added new SDK card linking to comprehensive SDK documentation
- Converted SDK documentation page to Blazor component
- Updated template download links to nuget.silverlabs.uk repository
- Implemented multi-stage Docker build with .NET SDK 9.0
- Created Blazor-optimized nginx configuration
- Preserved all original styling and animations
- Added .gitignore for Blazor build artifacts

Technical changes:
- New BlazorApp/ project structure with Components architecture
- MainLayout simplified (no default navigation)
- CSS ported to wwwroot (styles.css + sdk-styles.css)
- Multi-stage Dockerfile: Build with dotnet SDK, serve with nginx
- GitLab CI/CD pipeline compatible (auto-detects new Dockerfile)

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

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

Dockerfile

@@ -1,16 +1,26 @@
+# Build stage
+FROM mcr.microsoft.com/dotnet/sdk:9.0 AS build
+WORKDIR /src
+
+# Copy project file and restore dependencies
+COPY BlazorApp/SilverLabs.Website.csproj BlazorApp/
+RUN dotnet restore "BlazorApp/SilverLabs.Website.csproj"
+
+# Copy all source files
+COPY BlazorApp/ BlazorApp/
+
+# Build and publish the application
+WORKDIR /src/BlazorApp
+RUN dotnet publish "SilverLabs.Website.csproj" -c Release -o /app/publish
+
+# Runtime stage
 FROM nginx:alpine
 
-# Copy website files to nginx html directory
-COPY index.html /usr/share/nginx/html/
-COPY styles.css /usr/share/nginx/html/
-COPY script.js /usr/share/nginx/html/
-COPY logo.png /usr/share/nginx/html/
-
-# Copy SDK directory with templates
-COPY sdk/ /usr/share/nginx/html/sdk/
+# Copy the published Blazor app to nginx html directory
+COPY --from=build /app/publish/wwwroot /usr/share/nginx/html
 
 # Copy custom nginx configuration
-COPY nginx-site.conf /etc/nginx/conf.d/default.conf
+COPY nginx-blazor.conf /etc/nginx/conf.d/default.conf
 
 # Expose port 80
 EXPOSE 80