Add WebAPI middleware for multi-instance Roslyn Bridge routing

Add RoslynBridge.WebApi - ASP.NET Core 8.0 middleware that:
- Provides a centralized REST API for accessing multiple VS instances
- Manages instance registry with discovery by port, solution, or PID
- Proxies requests to the appropriate VS instance
- Tracks request/response history for debugging
- Auto-cleanup of stale instances via background service

Features:
- Health endpoints: /api/health, /api/health/ping
- Roslyn endpoints: /api/roslyn/projects, /api/roslyn/diagnostics, etc.
- Instance management: /api/instances (register, heartbeat, unregister)
- History tracking: /api/history, /api/history/stats
- Swagger UI at root (/) for API documentation
- CORS enabled for web applications

Services:
- InstanceRegistryService: Thread-safe registry of VS instances
- HistoryService: In-memory request/response history (max 1000 entries)
- InstanceCleanupService: Background service to remove stale instances
- RoslynBridgeClient: HTTP client for proxying to VS instances

Update RoslynBridge.sln to include RoslynBridge.WebApi project.

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

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

RoslynBridge.WebApi/Program.cs

@@ -0,0 +1,129 @@
+using Microsoft.OpenApi.Models;
+using RoslynBridge.WebApi.Middleware;
+using RoslynBridge.WebApi.Services;
+using System.Reflection;
+
+var builder = WebApplication.CreateBuilder(args);
+
+// Add Windows Service support
+builder.Services.AddWindowsService(options =>
+{
+    options.ServiceName = "RoslynBridge Web API";
+});
+
+// Configure CORS
+builder.Services.AddCors(options =>
+{
+    options.AddPolicy("AllowAll", policy =>
+    {
+        policy.AllowAnyOrigin()
+              .AllowAnyMethod()
+              .AllowAnyHeader();
+    });
+});
+
+// Add controllers
+builder.Services.AddControllers();
+
+// Register history service as singleton for in-memory storage
+builder.Services.AddSingleton<IHistoryService, HistoryService>();
+
+// Register instance registry service as singleton
+builder.Services.AddSingleton<IInstanceRegistryService, InstanceRegistryService>();
+
+// Register background service for cleaning up stale instances
+builder.Services.AddHostedService<InstanceCleanupService>();
+
+// Configure HttpClient for Roslyn Bridge
+var roslynBridgeUrl = builder.Configuration.GetValue<string>("RoslynBridge:BaseUrl") ?? "http://localhost:59123";
+builder.Services.AddHttpClient<IRoslynBridgeClient, RoslynBridgeClient>(client =>
+{
+    client.BaseAddress = new Uri(roslynBridgeUrl);
+    client.Timeout = TimeSpan.FromSeconds(30);
+});
+
+// Configure Swagger/OpenAPI
+builder.Services.AddEndpointsApiExplorer();
+builder.Services.AddSwaggerGen(options =>
+{
+    options.SwaggerDoc("v1", new OpenApiInfo
+    {
+        Title = "Roslyn Bridge Web API",
+        Version = "v1.0",
+        Description = "Modern web API middleware for Roslyn Bridge - connecting Claude AI to Visual Studio code analysis",
+        Contact = new OpenApiContact
+        {
+            Name = "Roslyn Bridge",
+            Url = new Uri("https://github.com/yourusername/roslynbridge")
+        }
+    });
+
+    // Include XML comments for better documentation
+    var xmlFilename = $"{Assembly.GetExecutingAssembly().GetName().Name}.xml";
+    var xmlPath = Path.Combine(AppContext.BaseDirectory, xmlFilename);
+    if (File.Exists(xmlPath))
+    {
+        options.IncludeXmlComments(xmlPath);
+    }
+
+    // Add operation tags
+    options.TagActionsBy(api =>
+    {
+        if (api.GroupName != null)
+        {
+            return new[] { api.GroupName };
+        }
+
+        if (api.ActionDescriptor is Microsoft.AspNetCore.Mvc.Controllers.ControllerActionDescriptor controllerActionDescriptor)
+        {
+            return new[] { controllerActionDescriptor.ControllerName };
+        }
+
+        return new[] { "Unknown" };
+    });
+});
+
+// Add health checks
+builder.Services.AddHealthChecks();
+
+var app = builder.Build();
+
+// Configure the HTTP request pipeline
+if (app.Environment.IsDevelopment())
+{
+    app.UseDeveloperExceptionPage();
+}
+
+// Enable Swagger in all environments for easy access
+app.UseSwagger();
+app.UseSwaggerUI(options =>
+{
+    options.SwaggerEndpoint("/swagger/v1/swagger.json", "Roslyn Bridge API v1");
+    options.RoutePrefix = string.Empty; // Serve Swagger UI at root
+    options.DocumentTitle = "Roslyn Bridge API";
+    options.DisplayRequestDuration();
+});
+
+app.UseHttpsRedirection();
+
+// Enable CORS
+app.UseCors("AllowAll");
+
+// Enable history tracking middleware (must be before authorization and controllers)
+app.UseHistoryTracking();
+
+app.UseAuthorization();
+
+// Map controllers
+app.MapControllers();
+
+// Map health check endpoint
+app.MapHealthChecks("/health");
+
+// Log startup information
+var logger = app.Services.GetRequiredService<ILogger<Program>>();
+logger.LogInformation("Roslyn Bridge Web API started");
+logger.LogInformation("Swagger UI available at: {Url}", app.Environment.IsDevelopment() ? "https://localhost:7001" : "/");
+logger.LogInformation("Connected to Roslyn Bridge at: {Url}", roslynBridgeUrl);
+
+app.Run();