feat: Initialize Zastava Webhook service with TLS and Authority authentication

- Added Program.cs to set up the web application with Serilog for logging, health check endpoints, and a placeholder admission endpoint.
- Configured Kestrel server to use TLS 1.3 and handle client certificates appropriately.
- Created StellaOps.Zastava.Webhook.csproj with necessary dependencies including Serilog and Polly.
- Documented tasks in TASKS.md for the Zastava Webhook project, outlining current work and exit criteria for each task.

src/StellaOps.Scanner.Analyzers.OS/Plugin/OsAnalyzerPluginCatalog.cs

@@ -0,0 +1,138 @@
+using System;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.IO;
+using System.Linq;
+using System.Reflection;
+using Microsoft.Extensions.Logging;
+using StellaOps.Plugin;
+using StellaOps.Plugin.Hosting;
+using StellaOps.Scanner.Analyzers.OS.Abstractions;
+using StellaOps.Scanner.Core.Security;
+
+namespace StellaOps.Scanner.Analyzers.OS.Plugin;
+
+public sealed class OsAnalyzerPluginCatalog
+{
+    private readonly ILogger<OsAnalyzerPluginCatalog> _logger;
+    private readonly IPluginCatalogGuard _guard;
+    private readonly ConcurrentDictionary<string, Assembly> _assemblies = new(StringComparer.OrdinalIgnoreCase);
+    private IReadOnlyList<IOSAnalyzerPlugin> _plugins = Array.Empty<IOSAnalyzerPlugin>();
+
+    public OsAnalyzerPluginCatalog(IPluginCatalogGuard guard, ILogger<OsAnalyzerPluginCatalog> logger)
+    {
+        _guard = guard ?? throw new ArgumentNullException(nameof(guard));
+        _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+    }
+
+    public IReadOnlyCollection<IOSAnalyzerPlugin> Plugins => _plugins;
+
+    public void LoadFromDirectory(string directory, bool seal = true)
+    {
+        ArgumentException.ThrowIfNullOrWhiteSpace(directory);
+        var fullDirectory = Path.GetFullPath(directory);
+
+        var options = new PluginHostOptions
+        {
+            PluginsDirectory = fullDirectory,
+            EnsureDirectoryExists = false,
+            RecursiveSearch = false,
+        };
+        options.SearchPatterns.Add("StellaOps.Scanner.Analyzers.*.dll");
+
+        var result = PluginHost.LoadPlugins(options, _logger);
+        if (result.Plugins.Count == 0)
+        {
+            _logger.LogWarning("No OS analyzer plug-ins discovered under '{Directory}'.", fullDirectory);
+        }
+
+        foreach (var descriptor in result.Plugins)
+        {
+            try
+            {
+                _guard.EnsureRegistrationAllowed(descriptor.AssemblyPath);
+                _assemblies[descriptor.AssemblyPath] = descriptor.Assembly;
+                _logger.LogInformation("Registered OS analyzer plug-in assembly '{Assembly}' from '{Path}'.",
+                    descriptor.Assembly.FullName,
+                    descriptor.AssemblyPath);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "Failed to register analyzer plug-in '{Path}'.", descriptor.AssemblyPath);
+            }
+        }
+
+        RefreshPluginList();
+
+        if (seal)
+        {
+            _guard.Seal();
+        }
+    }
+
+    public IReadOnlyList<IOSPackageAnalyzer> CreateAnalyzers(IServiceProvider services)
+    {
+        ArgumentNullException.ThrowIfNull(services);
+
+        if (_plugins.Count == 0)
+        {
+            _logger.LogWarning("No OS analyzer plug-ins available; scanning will skip OS package extraction.");
+            return Array.Empty<IOSPackageAnalyzer>();
+        }
+
+        var analyzers = new List<IOSPackageAnalyzer>(_plugins.Count);
+        foreach (var plugin in _plugins)
+        {
+            if (!IsPluginAvailable(plugin, services))
+            {
+                continue;
+            }
+
+            try
+            {
+                var analyzer = plugin.CreateAnalyzer(services);
+                if (analyzer is null)
+                {
+                    continue;
+                }
+
+                analyzers.Add(analyzer);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "Analyzer plug-in '{Plugin}' failed to create analyzer instance.", plugin.Name);
+            }
+        }
+
+        if (analyzers.Count == 0)
+        {
+            _logger.LogWarning("All OS analyzer plug-ins were unavailable.");
+            return Array.Empty<IOSPackageAnalyzer>();
+        }
+
+        analyzers.Sort(static (a, b) => string.CompareOrdinal(a.AnalyzerId, b.AnalyzerId));
+        return new ReadOnlyCollection<IOSPackageAnalyzer>(analyzers);
+    }
+
+    private void RefreshPluginList()
+    {
+        var assemblies = _assemblies.Values.ToArray();
+        var plugins = PluginLoader.LoadPlugins<IOSAnalyzerPlugin>(assemblies);
+        _plugins = plugins is IReadOnlyList<IOSAnalyzerPlugin> list
+            ? list
+            : new ReadOnlyCollection<IOSAnalyzerPlugin>(plugins.ToArray());
+    }
+
+    private static bool IsPluginAvailable(IOSAnalyzerPlugin plugin, IServiceProvider services)
+    {
+        try
+        {
+            return plugin.IsAvailable(services);
+        }
+        catch
+        {
+            return false;
+        }
+    }
+}