chore: organize solution into module folders (Core/Server/Drivers/Client/Tooling)

Group all 69 projects into category subfolders under src/ and tests/ so the
Rider Solution Explorer mirrors the module structure. Folders: Core, Server,
Drivers (with a nested Driver CLIs subfolder), Client, Tooling.

- Move every project folder on disk with git mv (history preserved as renames).
- Recompute relative paths in 57 .csproj files: cross-category ProjectReferences,
  the lib/ HintPath+None refs in Driver.Historian.Wonderware, and the external
  mxaccessgw refs in Driver.Galaxy and its test project.
- Rebuild ZB.MOM.WW.OtOpcUa.slnx with nested solution folders.
- Re-prefix project paths in functional scripts (e2e, compliance, smoke SQL,
  integration, install).

Build green (0 errors); unit tests pass. Docs left for a separate pass.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Components/Pages/Login.razor

@@ -0,0 +1,100 @@
+@page "/login"
+@using System.Security.Claims
+@using Microsoft.AspNetCore.Authentication
+@using Microsoft.AspNetCore.Authentication.Cookies
+@using ZB.MOM.WW.OtOpcUa.Admin.Security
+@inject IHttpContextAccessor Http
+@inject ILdapAuthService LdapAuth
+@inject NavigationManager Nav
+
+<div class="row justify-content-center mt-5">
+    <div class="col-md-5">
+        <div class="card">
+            <div class="card-body">
+                <h4 class="mb-4">OtOpcUa Admin — sign in</h4>
+
+                <EditForm Model="_input" OnValidSubmit="SignInAsync" FormName="login">
+                    <div class="mb-3">
+                        <label class="form-label">Username</label>
+                        <InputText @bind-Value="_input.Username" class="form-control" autocomplete="username"/>
+                    </div>
+                    <div class="mb-3">
+                        <label class="form-label">Password</label>
+                        <InputText type="password" @bind-Value="_input.Password" class="form-control" autocomplete="current-password"/>
+                    </div>
+
+                    @if (_error is not null) { <div class="alert alert-danger">@_error</div> }
+
+                    <button class="btn btn-primary w-100" type="submit" disabled="@_busy">
+                        @(_busy ? "Signing in…" : "Sign in")
+                    </button>
+                </EditForm>
+
+                <hr/>
+                <small class="text-muted">
+                    LDAP bind against the configured directory. Dev defaults to GLAuth on
+                    <code>localhost:3893</code>.
+                </small>
+            </div>
+        </div>
+    </div>
+</div>
+
+@code {
+    private sealed class Input
+    {
+        public string Username { get; set; } = string.Empty;
+        public string Password { get; set; } = string.Empty;
+    }
+
+    private Input _input = new();
+    private string? _error;
+    private bool _busy;
+
+    private async Task SignInAsync()
+    {
+        _error = null;
+        _busy = true;
+        try
+        {
+            if (string.IsNullOrWhiteSpace(_input.Username) || string.IsNullOrWhiteSpace(_input.Password))
+            {
+                _error = "Username and password are required";
+                return;
+            }
+
+            var result = await LdapAuth.AuthenticateAsync(_input.Username, _input.Password, CancellationToken.None);
+            if (!result.Success)
+            {
+                _error = result.Error ?? "Sign-in failed";
+                return;
+            }
+
+            if (result.Roles.Count == 0)
+            {
+                _error = "Sign-in succeeded but no Admin roles mapped for your LDAP groups. Contact your administrator.";
+                return;
+            }
+
+            var ctx = Http.HttpContext
+                ?? throw new InvalidOperationException("HttpContext unavailable at sign-in");
+
+            var claims = new List<Claim>
+            {
+                new(ClaimTypes.Name, result.DisplayName ?? result.Username ?? _input.Username),
+                new(ClaimTypes.NameIdentifier, _input.Username),
+            };
+            foreach (var role in result.Roles)
+                claims.Add(new Claim(ClaimTypes.Role, role));
+            foreach (var group in result.Groups)
+                claims.Add(new Claim("ldap_group", group));
+
+            var identity = new ClaimsIdentity(claims, CookieAuthenticationDefaults.AuthenticationScheme);
+            await ctx.SignInAsync(CookieAuthenticationDefaults.AuthenticationScheme,
+                new ClaimsPrincipal(identity));
+
+            ctx.Response.Redirect("/");
+        }
+        finally { _busy = false; }
+    }
+}