Initial commit: RR3 Community Server with web admin panel

- ASP.NET Core 8 REST API server
- 12 API endpoints matching EA Synergy protocol
- SQLite database with Entity Framework Core
- Web admin panel with Bootstrap 5
- User, Catalog, Session, Purchase management
- Comprehensive documentation

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

RR3CommunityServer/Data/RR3DbContext.cs

@@ -0,0 +1,106 @@
+using Microsoft.EntityFrameworkCore;
+
+namespace RR3CommunityServer.Data;
+
+public class RR3DbContext : DbContext
+{
+    public RR3DbContext(DbContextOptions<RR3DbContext> options) : base(options) { }
+
+    public DbSet<Device> Devices { get; set; }
+    public DbSet<User> Users { get; set; }
+    public DbSet<Session> Sessions { get; set; }
+    public DbSet<Purchase> Purchases { get; set; }
+    public DbSet<CatalogItem> CatalogItems { get; set; }
+
+    protected override void OnModelCreating(ModelBuilder modelBuilder)
+    {
+        base.OnModelCreating(modelBuilder);
+
+        // Seed some default catalog items
+        modelBuilder.Entity<CatalogItem>().HasData(
+            new CatalogItem
+            {
+                Id = 1,
+                Sku = "com.ea.rr3.gold_1000",
+                Name = "1000 Gold",
+                Type = "currency",
+                Price = 0.99m,
+                Available = true
+            },
+            new CatalogItem
+            {
+                Id = 2,
+                Sku = "com.ea.rr3.car_tier1",
+                Name = "Starter Car",
+                Type = "car",
+                Price = 0m,
+                Available = true
+            },
+            new CatalogItem
+            {
+                Id = 3,
+                Sku = "com.ea.rr3.upgrade_engine",
+                Name = "Engine Upgrade",
+                Type = "upgrade",
+                Price = 4.99m,
+                Available = true
+            }
+        );
+    }
+}
+
+// Database entities
+public class Device
+{
+    public int Id { get; set; }
+    public string DeviceId { get; set; } = string.Empty;
+    public string HardwareId { get; set; } = string.Empty;
+    public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
+    public DateTime LastSeenAt { get; set; } = DateTime.UtcNow;
+}
+
+public class User
+{
+    public int Id { get; set; }
+    public string SynergyId { get; set; } = string.Empty;
+    public string? DeviceId { get; set; }
+    public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
+    public string? Nickname { get; set; }
+}
+
+public class Session
+{
+    public int Id { get; set; }
+    public string SessionId { get; set; } = string.Empty;
+    public string? SynergyId { get; set; }
+    public string DeviceId { get; set; } = string.Empty;
+    public int? UserId { get; set; }
+    public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
+    public DateTime ExpiresAt { get; set; }
+}
+
+public class Purchase
+{
+    public int Id { get; set; }
+    public string SynergyId { get; set; } = string.Empty;
+    public string ItemId { get; set; } = string.Empty;
+    public string Sku { get; set; } = string.Empty;
+    public string OrderId { get; set; } = string.Empty;
+    public DateTime PurchaseTime { get; set; } = DateTime.UtcNow;
+    public string Token { get; set; } = string.Empty;
+    public decimal Price { get; set; }
+    public string Status { get; set; } = "approved";
+    // For web panel display
+    public int? UserId { get; set; }
+    public DateTime PurchaseDate => PurchaseTime;
+}
+
+public class CatalogItem
+{
+    public int Id { get; set; }
+    public string Sku { get; set; } = string.Empty;
+    public string Name { get; set; } = string.Empty;
+    public string Type { get; set; } = string.Empty;
+    public decimal Price { get; set; }
+    public bool Available { get; set; } = true;
+}