BREAKING: 3-tier split step 2 + engine-bridge v3 EgBim lambdas wired

Completes the Generic / HmEG-aware / App-specific separation started in
f6b6e74. The legacy EgPlugin / EngineBridge / EngineBridge.Client /
EngineBridge.Probe modules are moved into their proper tiers, namespaces
and csproj/sln entries are renamed, and the HmegDirectStateProvider
lambdas are finally populated with real handles from the EgBim plugin
host. A new Recordingtest.Architecture.Tests project enforces the tier
rule at build time.

Moves (git mv + csproj/RootNamespace/AssemblyName rename + sln):

  src/Recordingtest.EgPlugin
    -> src/Sut/EgBim/Recordingtest.Sut.EgBim.PluginHost
  src/Recordingtest.EngineBridge
    -> src/Hmeg/Recordingtest.Hmeg.Catalog
  src/Recordingtest.EngineBridge.Client
    -> src/Hmeg/Recordingtest.Hmeg.Bridge.Client
  src/Recordingtest.EngineBridge.Probe
    -> src/Hmeg/Recordingtest.Hmeg.Catalog.Probe

  tests/Recordingtest.EgPlugin.Tests
    -> tests/Sut/EgBim/Recordingtest.Sut.EgBim.PluginHost.Tests
  tests/Recordingtest.EngineBridge.Tests
    -> tests/Hmeg/Recordingtest.Hmeg.Catalog.Tests
  tests/Recordingtest.EngineBridge.IntegrationTests
    -> tests/Hmeg/Recordingtest.Hmeg.Catalog.IntegrationTests

Namespace rename applied across all .cs files and csproj RootNamespace:

  Recordingtest.EgPlugin           -> Recordingtest.Sut.EgBim.PluginHost
  Recordingtest.EngineBridge       -> Recordingtest.Hmeg.Catalog
  Recordingtest.EngineBridge.Client -> Recordingtest.Hmeg.Bridge.Client
  Recordingtest.EngineBridge.Probe -> Recordingtest.Hmeg.Catalog.Probe

New: tests/Recordingtest.Architecture.Tests/

  DependencyGraphTests walks Assembly.GetReferencedAssemblies() for each
  tier and fails if a forbidden reference leaks in:
    - Generic modules must not reference HmEG or any app-specific DLL
    - HmEG-aware modules must not reference app-specific DLLs
    - Recordingtest.Hmeg.Bridge must reference HmEG (positive check)
  11 tests, all passing. Prevents future drift from CLAUDE.md §8.1.

Engine-bridge v3 wire-up (HmEgBridgePlugin.BuildProvider):

  Previously the HmegDirectStateProvider lambdas returned null and the
  chain fell through to reflection. They now call directly into the
  EditorPlugin base class that HmEgBridgePlugin inherits:

    spaceProvider    = () => RootSpace
                           // AppManager.ViewportManager.RootSpace
    viewportProvider = () => View
                           // EGViewport : Control, HmEGViewport
    documentPathProvider = () => AppManager?.FileManager?.CurrentFile

  Every lambda is wrapped in try/catch so plugin construction still
  cannot throw back into the SUT. Editor02.HmEGAppManager.dll added as
  a reference on Recordingtest.Sut.EgBim.PluginHost.csproj — app-
  specific tier, which is allowed by the architecture tests.

Entry points were confirmed from read-only review of the SUT sources at
  D:\GiteaAll\EG-BIM_Modeler\EditorPluginInterface\EditorPlugin.cs
  D:\GiteaAll\EG-BIM_Modeler\HmEGApplicationManagementLibrary\HmEGAppManager.cs
  D:\GiteaAll\EG-BIM_Modeler\HmEGApplicationManagementLibrary\SubManager\FileManager.cs

closing out Q1/Q2/Q6/Q7 from docs/hmeg-api-survey.md.

Tests: 115 -> 126 (+11 Architecture), 0 failures.

Next step: live verification of /scene /camera /selection with a real
SUT session; any discrepancy in HmegDirectStateProvider reflection will
be tightened after observing real HmEG camera field names.

Ref: #10 follow-up, #14 follow-up, docs/contracts/generic-sut-split.md.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/Hmeg/Recordingtest.Hmeg.Bridge.Client/EngineBridgeException.cs

@@ -0,0 +1,11 @@
+namespace Recordingtest.Hmeg.Bridge.Client;
+
+public sealed class EngineBridgeException : Exception
+{
+    public string Endpoint { get; }
+    public EngineBridgeException(string endpoint, string message, Exception? inner = null)
+        : base($"engine-bridge {endpoint}: {message}", inner)
+    {
+        Endpoint = endpoint;
+    }
+}

src/Hmeg/Recordingtest.Hmeg.Bridge.Client/HmEgHttpSnapshot.cs

@@ -0,0 +1,122 @@
+using System.Net.Http;
+using System.Text.Json;
+using Recordingtest.Hmeg.Catalog;
+
+namespace Recordingtest.Hmeg.Bridge.Client;
+
+public sealed class HmEgHttpSnapshot : IEngineSnapshot, IDisposable
+{
+    public const string DefaultBaseUrl = "http://localhost:38080";
+    private readonly HttpClient _http;
+    private readonly bool _ownsClient;
+    private readonly string _baseUrl;
+
+    public HmEgHttpSnapshot(string baseUrl = DefaultBaseUrl, HttpClient? httpClient = null, TimeSpan? timeout = null)
+    {
+        _baseUrl = baseUrl.TrimEnd('/');
+        if (httpClient is null)
+        {
+            _http = new HttpClient { Timeout = timeout ?? TimeSpan.FromSeconds(2) };
+            _ownsClient = true;
+        }
+        else
+        {
+            _http = httpClient;
+            if (timeout.HasValue) _http.Timeout = timeout.Value;
+            _ownsClient = false;
+        }
+    }
+
+    public IReadOnlyList<string> SelectedObjectIds
+    {
+        get
+        {
+            using var doc = Get("/selection");
+            var arr = doc.RootElement.GetProperty("selected_ids");
+            var list = new List<string>(arr.GetArrayLength());
+            foreach (var e in arr.EnumerateArray()) list.Add(e.GetString() ?? string.Empty);
+            return list;
+        }
+    }
+
+    public CameraState Camera
+    {
+        get
+        {
+            using var doc = Get("/camera");
+            var r = doc.RootElement;
+            return new CameraState(
+                ToArray(r.GetProperty("eye")),
+                ToArray(r.GetProperty("target")),
+                ToArray(r.GetProperty("up")),
+                r.GetProperty("fov").GetDouble());
+        }
+    }
+
+    public SceneSummary Scene
+    {
+        get
+        {
+            using var doc = Get("/scene");
+            var r = doc.RootElement;
+            string? path = r.TryGetProperty("document_path", out var dp) && dp.ValueKind == JsonValueKind.String ? dp.GetString() : null;
+            return new SceneSummary(r.GetProperty("object_count").GetInt32(), path);
+        }
+    }
+
+    public bool IsRenderComplete
+    {
+        get
+        {
+            using var doc = Get("/render");
+            return doc.RootElement.GetProperty("complete").GetBoolean();
+        }
+    }
+
+    public bool IsHealthy
+    {
+        get
+        {
+            try
+            {
+                using var doc = Get("/health");
+                return doc.RootElement.TryGetProperty("status", out var s) && s.GetString() == "ok";
+            }
+            catch (EngineBridgeException) { return false; }
+        }
+    }
+
+    private JsonDocument Get(string endpoint)
+    {
+        try
+        {
+            using var resp = _http.GetAsync(_baseUrl + endpoint).GetAwaiter().GetResult();
+            if (!resp.IsSuccessStatusCode)
+                throw new EngineBridgeException(endpoint, $"HTTP {(int)resp.StatusCode}");
+            var body = resp.Content.ReadAsStringAsync().GetAwaiter().GetResult();
+            return JsonDocument.Parse(body);
+        }
+        catch (EngineBridgeException) { throw; }
+        catch (TaskCanceledException ex)
+        {
+            throw new EngineBridgeException(endpoint, "timeout", ex);
+        }
+        catch (Exception ex)
+        {
+            throw new EngineBridgeException(endpoint, ex.Message, ex);
+        }
+    }
+
+    private static double[] ToArray(JsonElement e)
+    {
+        var arr = new double[e.GetArrayLength()];
+        int i = 0;
+        foreach (var item in e.EnumerateArray()) arr[i++] = item.GetDouble();
+        return arr;
+    }
+
+    public void Dispose()
+    {
+        if (_ownsClient) _http.Dispose();
+    }
+}

src/Hmeg/Recordingtest.Hmeg.Bridge.Client/Recordingtest.Hmeg.Bridge.Client.csproj

@@ -0,0 +1,13 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+    <RootNamespace>Recordingtest.Hmeg.Bridge.Client</RootNamespace>
+    <AssemblyName>Recordingtest.Hmeg.Bridge.Client</AssemblyName>
+  </PropertyGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\Recordingtest.Hmeg.Catalog\Recordingtest.Hmeg.Catalog.csproj" />
+  </ItemGroup>
+</Project>