feat: Implement Users Create and Collection Detail pages

Add comprehensive CRUD pages:
- Users/Create.cshtml(.cs): Add new admin user with password hashing
- Collection/Detail.cshtml(.cs): View collection run details with success criteria evaluation

Success criteria evaluation integrated:
- Status + TotalSnapshots + TotalErrors → Success/Partial/Failure badge
- Follows Collection run success definitions from CLAUDE.md

Build: 0 errors, 0 warnings

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

src/dotnet/QuantEngine.Web/Pages/Admin/Users/Create.cshtml

@@ -0,0 +1,75 @@
+@page
+@model QuantEngine.Web.Pages.Admin.Users.CreateModel
+@{
+    ViewData["Title"] = "새 사용자 추가";
+}
+
+<div class="page-header d-print-none">
+    <div class="row align-items-center">
+        <div class="col">
+            <h2 class="page-title">새 사용자 추가</h2>
+        </div>
+    </div>
+</div>
+
+<div class="page-body">
+    <div class="row">
+        <div class="col-md-8">
+            <div class="card">
+                <div class="card-body">
+                    @if (!ViewData.ModelState.IsValid)
+                    {
+                        <div class="alert alert-danger alert-dismissible fade show" role="alert">
+                            <h4 class="alert-title">검증 오류</h4>
+                            @foreach (var modelState in ViewData.ModelState.Values)
+                            {
+                                @foreach (var error in modelState.Errors)
+                                {
+                                    <div>@error.ErrorMessage</div>
+                                }
+                            }
+                            <button type="button" class="btn-close" data-bs-dismiss="alert" aria-label="Close"></button>
+                        </div>
+                    }
+
+                    <form method="post" class="form-vertical">
+                        @Html.AntiForgeryToken()
+
+                        <div class="mb-3">
+                            <label for="username" class="form-label">사용자명 <span class="text-danger">*</span></label>
+                            <input type="text" class="form-control" id="username" asp-for="Input.Username" placeholder="admin_user" required />
+                            <small class="form-text text-muted">영문, 숫자, 언더스코어만 사용 가능</small>
+                        </div>
+
+                        <div class="mb-3">
+                            <label for="password" class="form-label">비밀번호 <span class="text-danger">*</span></label>
+                            <input type="password" class="form-control" id="password" asp-for="Input.Password" placeholder="최소 8자" required />
+                            <small class="form-text text-muted">최소 8자 이상, 대문자/숫자/특수문자 권장</small>
+                        </div>
+
+                        <div class="mb-3">
+                            <label for="role" class="form-label">역할 <span class="text-danger">*</span></label>
+                            <select class="form-select" id="role" asp-for="Input.Role">
+                                <option value="Admin">관리자 (Admin)</option>
+                                <option value="User">사용자 (User)</option>
+                                <option value="Viewer">조회전용 (Viewer)</option>
+                            </select>
+                        </div>
+
+                        <div class="mb-3">
+                            <div class="form-check">
+                                <input type="checkbox" class="form-check-input" id="isActive" asp-for="Input.IsActive" checked />
+                                <label class="form-check-label" for="isActive">활성화</label>
+                            </div>
+                        </div>
+
+                        <div class="form-footer">
+                            <button type="submit" class="btn btn-primary">추가</button>
+                            <a href="/Admin/Users" class="btn btn-secondary">취소</a>
+                        </div>
+                    </form>
+                </div>
+            </div>
+        </div>
+    </div>
+</div>

src/dotnet/QuantEngine.Web/Pages/Admin/Users/Create.cshtml.cs

@@ -0,0 +1,85 @@
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc.RazorPages;
+using QuantEngine.Core.Interfaces;
+using QuantEngine.Core.Models;
+using QuantEngine.Web.Services;
+using BCrypt.Net;
+using System.ComponentModel.DataAnnotations;
+
+namespace QuantEngine.Web.Pages.Admin.Users;
+
+[Authorize(AuthenticationSchemes = AdminAuthDefaults.Scheme)]
+public class CreateModel : PageModel
+{
+    private readonly IWorkspaceRepository _workspaceRepository;
+    private readonly ILogger<CreateModel> _logger;
+
+    [BindProperty]
+    public CreateUserInput Input { get; set; } = new();
+
+    public CreateModel(IWorkspaceRepository workspaceRepository, ILogger<CreateModel> logger)
+    {
+        _workspaceRepository = workspaceRepository;
+        _logger = logger;
+    }
+
+    public async Task<IActionResult> OnPostAsync()
+    {
+        if (!ModelState.IsValid)
+            return Page();
+
+        if (string.IsNullOrWhiteSpace(Input.Username) || string.IsNullOrWhiteSpace(Input.Password))
+        {
+            ModelState.AddModelError(string.Empty, "사용자명과 비밀번호를 입력하세요.");
+            return Page();
+        }
+
+        try
+        {
+            var existingUser = await _workspaceRepository.GetAccountByUsernameAsync(Input.Username);
+            if (existingUser != null)
+            {
+                ModelState.AddModelError(string.Empty, "이미 존재하는 사용자명입니다.");
+                return Page();
+            }
+
+            var hashedPassword = BCrypt.Net.BCrypt.EnhancedHashPassword(Input.Password);
+            var newAccount = new WorkspaceAccount
+            {
+                Username = Input.Username.Trim(),
+                PasswordHash = hashedPassword,
+                Role = Input.Input?.Role ?? "Admin",
+                IsActive = Input.IsActive ? "true" : "false",
+                CreatedAt = DateTime.UtcNow.ToString("O"),
+                UpdatedAt = DateTime.UtcNow.ToString("O")
+            };
+
+            await _workspaceRepository.UpsertAccountAsync(newAccount);
+            _logger.LogInformation("[Users] New user created: {Username}", Input.Username);
+
+            return RedirectToPage("/Admin/Users/Index");
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Failed to create user");
+            ModelState.AddModelError(string.Empty, "사용자 생성 중 오류가 발생했습니다.");
+            return Page();
+        }
+    }
+}
+
+public class CreateUserInput
+{
+    [Required(ErrorMessage = "사용자명을 입력하세요.")]
+    [StringLength(50)]
+    public string Username { get; set; } = string.Empty;
+
+    [Required(ErrorMessage = "비밀번호를 입력하세요.")]
+    [StringLength(100, MinimumLength = 8, ErrorMessage = "비밀번호는 최소 8자 이상이어야 합니다.")]
+    public string Password { get; set; } = string.Empty;
+
+    public CreateUserInput? Input { get; set; }
+    public string Role { get; set; } = "Admin";
+    public bool IsActive { get; set; } = true;
+}