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/Controllers/UserController.cs

@@ -0,0 +1,85 @@
+using Microsoft.AspNetCore.Mvc;
+using RR3CommunityServer.Models;
+using RR3CommunityServer.Services;
+
+namespace RR3CommunityServer.Controllers;
+
+[ApiController]
+[Route("user/api/android")]
+public class UserController : ControllerBase
+{
+    private readonly IUserService _userService;
+    private readonly ISessionService _sessionService;
+    private readonly ILogger<UserController> _logger;
+
+    public UserController(IUserService userService, ISessionService sessionService, ILogger<UserController> logger)
+    {
+        _userService = userService;
+        _sessionService = sessionService;
+        _logger = logger;
+    }
+
+    [HttpGet("getDeviceID")]
+    public async Task<ActionResult<SynergyResponse<DeviceIdResponse>>> GetDeviceId(
+        [FromQuery] string? deviceId,
+        [FromQuery] string hardwareId = "")
+    {
+        _logger.LogInformation("GetDeviceID request: existing={Existing}, hardware={Hardware}", deviceId, hardwareId);
+
+        var newDeviceId = await _userService.GetOrCreateDeviceId(deviceId, hardwareId);
+        var synergyId = await _userService.GetOrCreateSynergyId(newDeviceId);
+        var sessionId = await _sessionService.CreateSession(synergyId);
+
+        var response = new SynergyResponse<DeviceIdResponse>
+        {
+            resultCode = 0,
+            message = "Success",
+            data = new DeviceIdResponse
+            {
+                deviceId = newDeviceId,
+                synergyId = synergyId,
+                timestamp = DateTimeOffset.UtcNow.ToUnixTimeSeconds()
+            }
+        };
+
+        return Ok(response);
+    }
+
+    [HttpGet("validateDeviceID")]
+    public async Task<ActionResult<SynergyResponse<object>>> ValidateDeviceId([FromQuery] string deviceId)
+    {
+        _logger.LogInformation("ValidateDeviceID: {DeviceId}", deviceId);
+
+        var result = await _userService.ValidateDeviceId(deviceId);
+
+        var response = new SynergyResponse<object>
+        {
+            resultCode = result == "valid" ? 0 : -1,
+            message = result == "valid" ? "Device validated" : "Device not found",
+            data = new { status = result }
+        };
+
+        return Ok(response);
+    }
+
+    [HttpGet("getAnonUid")]
+    public async Task<ActionResult<SynergyResponse<AnonUidResponse>>> GetAnonUid()
+    {
+        _logger.LogInformation("GetAnonUid request");
+
+        var anonUid = await _userService.GetOrCreateAnonUid();
+
+        var response = new SynergyResponse<AnonUidResponse>
+        {
+            resultCode = 0,
+            message = "Success",
+            data = new AnonUidResponse
+            {
+                anonUid = anonUid,
+                expiresAt = DateTimeOffset.UtcNow.AddDays(30).ToUnixTimeSeconds()
+            }
+        };
+
+        return Ok(response);
+    }
+}