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>

tests/Server/ZB.MOM.WW.OtOpcUa.Admin.Tests/LdapAuthServiceTests.cs

@@ -0,0 +1,45 @@
+using System.Reflection;
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.Admin.Security;
+
+namespace ZB.MOM.WW.OtOpcUa.Admin.Tests;
+
+/// <summary>
+///     Deterministic unit tests for the LDAP input-sanitization and DN-parsing helpers. Live LDAP
+///     bind against the GLAuth dev instance is covered by the admin-browser smoke path, not here,
+///     because unit runs must not depend on a running external service.
+/// </summary>
+[Trait("Category", "Unit")]
+public sealed class LdapAuthServiceTests
+{
+    private static string EscapeLdapFilter(string input) =>
+        (string)typeof(LdapAuthService)
+            .GetMethod("EscapeLdapFilter", BindingFlags.NonPublic | BindingFlags.Static)!
+            .Invoke(null, [input])!;
+
+    private static string ExtractFirstRdnValue(string dn) =>
+        (string)typeof(LdapAuthService)
+            .GetMethod("ExtractFirstRdnValue", BindingFlags.NonPublic | BindingFlags.Static)!
+            .Invoke(null, [dn])!;
+
+    [Theory]
+    [InlineData("alice", "alice")]
+    [InlineData("a(b)c", "a\\28b\\29c")]
+    [InlineData("wildcard*", "wildcard\\2a")]
+    [InlineData("back\\slash", "back\\5cslash")]
+    public void Escape_filter_replaces_control_chars(string input, string expected)
+    {
+        EscapeLdapFilter(input).ShouldBe(expected);
+    }
+
+    [Theory]
+    [InlineData("ou=ReadOnly,ou=groups,dc=lmxopcua,dc=local", "ReadOnly")]
+    [InlineData("cn=admin,dc=corp,dc=com", "admin")]
+    [InlineData("ReadOnly", "ReadOnly")] // no '=' → pass through
+    [InlineData("ou=OnlySegment", "OnlySegment")]
+    public void Extract_first_RDN_strips_the_first_attribute_value(string dn, string expected)
+    {
+        ExtractFirstRdnValue(dn).ShouldBe(expected);
+    }
+}