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>

BlazorApp/Components/Pages/Home.razor

@@ -0,0 +1,66 @@
+@page "/"
+
+<PageTitle>SilverLabs - Innovation Gateway</PageTitle>
+
+<div class="main-content visible">
+    <header class="header">
+        <img src="logo.png" alt="SilverLabs Logo" class="logo">
+    </header>
+
+    <main class="main">
+        <h1 class="title">Welcome to SilverLabs</h1>
+        <p class="subtitle">Your Innovation Gateway</p>
+
+        <div class="gateway-grid">
+            <a href="https://helpdesk.silverlabs.uk" class="gateway-card">
+                <div class="card-icon">
+                    <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+                        <circle cx="12" cy="12" r="10"></circle>
+                        <path d="M9.09 9a3 3 0 0 1 5.83 1c0 2-3 3-3 3"></path>
+                        <line x1="12" y1="17" x2="12.01" y2="17"></line>
+                    </svg>
+                </div>
+                <h2 class="card-title">Help Desk</h2>
+                <p class="card-description">Support & Assistance</p>
+            </a>
+
+            <a href="https://appstore.silverlabs.uk" class="gateway-card">
+                <div class="card-icon">
+                    <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+                        <rect x="3" y="3" width="7" height="7"></rect>
+                        <rect x="14" y="3" width="7" height="7"></rect>
+                        <rect x="14" y="14" width="7" height="7"></rect>
+                        <rect x="3" y="14" width="7" height="7"></rect>
+                    </svg>
+                </div>
+                <h2 class="card-title">App Store</h2>
+                <p class="card-description">Applications & Tools</p>
+            </a>
+
+            <a href="https://cloud.silverlabs.uk" class="gateway-card">
+                <div class="card-icon">
+                    <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+                        <path d="M18 10h-1.26A8 8 0 1 0 9 20h9a5 5 0 0 0 0-10z"></path>
+                    </svg>
+                </div>
+                <h2 class="card-title">Cloud</h2>
+                <p class="card-description">Storage & Collaboration</p>
+            </a>
+
+            <a href="/sdk" class="gateway-card">
+                <div class="card-icon">
+                    <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+                        <polyline points="16 18 22 12 16 6"></polyline>
+                        <polyline points="8 6 2 12 8 18"></polyline>
+                    </svg>
+                </div>
+                <h2 class="card-title">SDK</h2>
+                <p class="card-description">Developer Resources</p>
+            </a>
+        </div>
+    </main>
+
+    <footer class="footer">
+        <p>&copy; 2025 SilverLabs. All rights reserved.</p>
+    </footer>
+</div>