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/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Runtime/GalaxyAlarmTransition.cs

@@ -0,0 +1,36 @@
+using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Runtime;
+
+/// <summary>
+///     Decoded MXAccess alarm transition surfaced by <see cref="EventPump"/>.
+///     The driver wraps this into <see cref="AlarmEventArgs"/> on the
+///     <see cref="IAlarmSource.OnAlarmEvent"/> path; the richer fields
+///     (operator user/comment, original raise time, category) become available
+///     on the OPC UA Part 9 condition once <c>AlarmEventArgs</c> is extended in
+///     the client-surface refresh PR (E.7).
+/// </summary>
+internal sealed record GalaxyAlarmTransition(
+    string AlarmFullReference,
+    string SourceObjectReference,
+    string AlarmTypeName,
+    GalaxyAlarmTransitionKind TransitionKind,
+    AlarmSeverity SeverityBucket,
+    int OpcUaSeverity,
+    int RawMxAccessSeverity,
+    DateTime? OriginalRaiseTimestampUtc,
+    DateTime TransitionTimestampUtc,
+    string OperatorUser,
+    string OperatorComment,
+    string Category,
+    string Description);
+
+/// <summary>Kind of alarm state change observed by <see cref="EventPump"/>.</summary>
+internal enum GalaxyAlarmTransitionKind
+{
+    Unspecified = 0,
+    Raise = 1,
+    Acknowledge = 2,
+    Clear = 3,
+    Retrigger = 4,
+}