arch(runtime): establish presentation-independent boundary

Create the dependency-only Runtime project before moving any gameplay owner, enforce its direct, transitive, source, and load-time closure, and pin coherent lifetime-group extraction plus retryable teardown ordering. No production behavior changes in J0.

Validated by the four focused Runtime boundary tests, a zero-error Release solution build, and 8,406 passing Release tests with five pre-existing skips.

Co-authored-by: Codex <codex@openai.com>

AcDream.slnx

@@ -8,6 +8,7 @@
     <Project Path="src/AcDream.Core.Net/AcDream.Core.Net.csproj" />
     <Project Path="src/AcDream.Plugin.Abstractions/AcDream.Plugin.Abstractions.csproj" />
     <Project Path="src/AcDream.Plugins.Smoke/AcDream.Plugins.Smoke.csproj" />
+    <Project Path="src/AcDream.Runtime/AcDream.Runtime.csproj" />
     <Project Path="src/AcDream.UI.Abstractions/AcDream.UI.Abstractions.csproj" />
     <Project Path="src/AcDream.UI.ImGui/AcDream.UI.ImGui.csproj" />
   </Folder>
@@ -22,6 +23,7 @@
     <Project Path="tests/AcDream.Core.Tests.Fixtures.HelloPlugin/AcDream.Core.Tests.Fixtures.HelloPlugin.csproj" />
     <Project Path="tests/AcDream.Core.Tests/AcDream.Core.Tests.csproj" />
     <Project Path="tests/AcDream.Core.Net.Tests/AcDream.Core.Net.Tests.csproj" />
+    <Project Path="tests/AcDream.Runtime.Tests/AcDream.Runtime.Tests.csproj" />
     <Project Path="tests/AcDream.UI.Abstractions.Tests/AcDream.UI.Abstractions.Tests.csproj" />
   </Folder>
 </Solution>

docs/architecture/acdream-architecture.md

@@ -203,6 +203,11 @@ src/
     NetClient.cs              -> done
     Messages/                 -> done (CreateObject, MoveToState, etc.)
 
+  AcDream.Runtime/           presentation-independent client kernel boundary
+    RuntimeAssemblyMarker.cs  -> J0 dependency boundary; owner moves start after I6/I7
+    -> may reference Core, Core.Net, Content, and Plugin.Abstractions only
+    -> must never reference App, UI, Silk.NET, OpenAL, Arch, or ImGui
+  
   AcDream.Plugin.Abstractions/  Layer 5: plugin interfaces
     IAcDreamPlugin.cs         -> done
     IPluginHost.cs            -> done

docs/architecture/code-structure.md

@@ -166,6 +166,7 @@ Today:
 
 - `tests/AcDream.Core.Tests/` ← `src/AcDream.Core/`
 - `tests/AcDream.Core.Net.Tests/` ← `src/AcDream.Core.Net/`
+- `tests/AcDream.Runtime.Tests/` ← `src/AcDream.Runtime/`
 - `tests/AcDream.UI.Abstractions.Tests/` ← `src/AcDream.UI.Abstractions/`
 - `tests/AcDream.App.Tests/` ← `src/AcDream.App/`
 

docs/plans/2026-07-24-modern-runtime-architecture.md

@@ -2,8 +2,11 @@
 
 **Date:** 2026-07-24
 
-**Status:** Slices A–H and I0–I3 are complete. Slices F–L were explicitly
+**Status:** Slices A–H are complete. Slice I6's flat-authoritative production
-approved 2026-07-24; Slice I4 is active.
+cutover is committed and awaits the final user collision/visual gate before
+parsed-graph deletion. Slices F–L were explicitly approved 2026-07-24. Slice
+J0's dependency-boundary preparation is complete without moving gameplay
+owners. J1 remains behind the I6/I7 user collision/visual closeout.
 
 **Scope:** Reconcile and sequence the existing Modern Pipeline (`MP`) and
 Linux/headless (`LH`) tracks using the 2026-07-24 connected performance audit.
@@ -499,6 +502,41 @@ It exposes:
 - Deterministic `Tick`.
 - Retryable, complete shutdown.
 
+#### 9.2.1 Structural teardown protocol
+
+Every graphical or headless host follows one retryable, generation-scoped
+teardown transaction. New runtime owners register through the same
+`CompositionAcquisitionScope` lease discipline already used by the graphical
+composition root; release order is encoded by leases and acknowledgements,
+never remembered by callers.
+
+1. **Cancel scheduler generations.** Make commands inert, cancel the active
+   session/runtime generation, stop new receive publication, and prevent any
+   timer, bot, plugin, or worker callback from creating more work for it.
+2. **Drain or poison journals and queues.** Detach inbound producers, drain
+   already-accepted ordered events through the generation boundary, then
+   poison every command/event/delta queue so delayed callbacks fail against
+   their exact generation instead of entering a replacement session.
+3. **Unpublish presentation.** The graphical host consumes the final ordered
+   withdrawals and acknowledges that the render scene, retained gameplay UI,
+   audio/effect projections, selection, radar, and private viewports no longer
+   expose the runtime generation. Headless hosts acknowledge this stage
+   immediately because they construct no presentation owners.
+4. **Release residency after fences.** Withdraw content owners, finish
+   streaming/landblock retirement, and allow GPU-backed stores to retire only
+   after their existing frame-flight fences signal. A failed fence or release
+   retains the exact unfinished lease and resumes without replaying completed
+   stages.
+5. **Release the shared `ContentStore` last.** Session-scoped collision/content
+   leases go away before the runtime instance. The immutable mapped content
+   store outlives every runtime and presentation host and is disposed only by
+   the process host after all registered sessions have acknowledged teardown.
+
+Logout, session reset, mid-portal disconnect, reconnect replacement, ordinary
+window close, and construction rollback all use this protocol. No stage may
+clear another generation's state, and no teardown failure may be converted
+into a best-effort purge.
+
 ### 9.3 Hosts
 
 `GraphicalGameHost` provides input, camera, rendering, UI, audio, frame pacing,

docs/plans/2026-07-25-modern-runtime-slice-j.md

@@ -0,0 +1,230 @@
+# Modern runtime Slice J — presentation-independent runtime
+
+**Status:** J0 COMPLETE — lifetime plan, project boundary, and dependency
+guards; J1 waits for the Slice I6/I7 user collision/visual closeout
+**Parent:** `2026-07-24-modern-runtime-architecture.md`, Slice J
+**Authorization:** the user approved Slices F–L, including the otherwise-frozen
+Slice J gameplay-owner moves, on 2026-07-24
+**Purpose:** move the existing authoritative client kernel into a
+presentation-independent assembly without creating a second world, changing
+retail behavior, or making the graphical host a special case.
+
+Slice J is a lifetime-group campaign, not one large move. Each sub-slice keeps
+the graphical client on the same owner instance, establishes host parity, and
+deletes the replaced App production path before the next group moves.
+
+## 1. Fixed invariants
+
+1. `LiveEntityRuntime` remains the sole server-GUID/incarnation owner. There is
+   never a second GUID map or synchronized gameplay world.
+2. Runtime types do not reference `AcDream.App`, either UI assembly, Silk.NET,
+   OpenAL, Arch, ImGui, a native window, or an OpenGL resource.
+3. App projection state is keyed by runtime-issued local entity identity plus
+   incarnation. It may not recover or mirror server GUID ownership.
+4. The accepted update order, packet ordering, timestamp gates, outbound
+   cadence, and retail-shaped gameplay algorithms do not change during the
+   extraction.
+5. Contracts expose borrowed/immutable views, typed commands, and ordered
+   deltas. They do not expose App render components or deep per-frame object
+   graphs.
+6. All clocks, queues, random sources, diagnostics identity, plugin behavior,
+   and mutable caches that can differ between sessions are instance-scoped.
+7. Immutable prepared content may be shared. Session state and mutable query
+   scratch may not.
+8. Every new owner participates in the structural teardown protocol in parent
+   plan §9.2.1 through acquisition leases and exact acknowledgements.
+9. A headless construction path is proved after every coherent move. “No
+   window” means no App, Silk, OpenAL, retained UI, particle, or render assembly
+   is loaded—not a hidden graphical process.
+10. The user collision/visual gate for Slice I6 still controls parsed-graph
+    deletion. J0 may land independently; gameplay-owner moves begin only after
+    the active I6/I7 closeout has reconciled the final collision owner shape.
+
+## 2. Target dependency direction
+
+```text
+AcDream.App ───────────────► AcDream.Runtime
+AcDream.Headless (Slice K) ─► AcDream.Runtime
+                               ├──► AcDream.Core.Net
+                               ├──► AcDream.Core
+                               ├──► AcDream.Content
+                               └──► AcDream.Plugin.Abstractions
+
+AcDream.Runtime -X► AcDream.App / AcDream.UI.* / Silk.NET / OpenAL / Arch
+```
+
+Runtime-emitted entity events contain incarnation, transform, flags, and
+property deltas only. An App-side projection adapter translates them into
+`IRenderScene` journal operations. Render vocabulary never enters Runtime.
+
+## 3. Teardown transaction
+
+The exact order is:
+
+1. cancel scheduler/session generations and make commands inert;
+2. detach producers, drain accepted ordered events, and poison queues;
+3. withdraw and acknowledge graphical presentation;
+4. retire session residence and GPU-backed owners through existing fences;
+5. dispose the process-owned immutable `ContentStore` only after every runtime
+   and host has completed.
+
+Completed stages never replay. Failure retains the exact remaining suffix.
+Logout, reset, mid-portal disconnect, reconnect replacement, construction
+rollback, and native close all traverse the same transaction.
+
+## 4. Execution slices
+
+### J0 — boundary, plan, and dependency enforcement
+
+**Completed 2026-07-25.**
+
+- Add `AcDream.Runtime` and `AcDream.Runtime.Tests`.
+- Permit references only to Core, Core.Net, Content, and Plugin.Abstractions.
+- Add App → Runtime as the future host dependency; Runtime never references
+  App.
+- Add direct-reference, dependency-closure, source-project, and assembly-load
+  guards that fail if a presentation/backend dependency enters Runtime.
+- Add only an assembly boundary marker; do not introduce a facade
+  `GameRuntime`, mirror state, or move behavior in J0.
+- Pin this lifetime-group plan and parent-plan teardown protocol.
+
+Gate: Release build and full tests pass; the Runtime test process loads no App,
+UI, Silk, OpenAL, Arch, or ImGui assembly; graphical behavior is byte-for-byte
+unchanged because no runtime path changed.
+
+Evidence: four focused dependency tests pass, the Release solution builds with
+zero errors, and the complete Release suite passes 8,406 tests with five
+pre-existing skips. The exact rollback commit is recorded below after landing.
+
+### J1 — read, command, event, clock, and lifecycle contracts
+
+- Define `IGameRuntimeView`, typed command interfaces, ordered event/delta
+  records, instance clock, lifecycle states, generation tokens, and teardown
+  acknowledgements.
+- Build App adapters over the current owners first. Adapters borrow; they do
+  not copy mutable collections or own lifetime.
+- Add a normalized parity trace of accepted inbound events, runtime commands,
+  state revisions, and lifecycle edges.
+- Prove press-time graphical input reaches the same current owners through the
+  command contract with no extra frame of latency.
+
+Gate: adapter and direct-host traces are identical over deterministic session,
+entity, inventory, chat, movement, and portal fixtures; no canonical owner has
+moved yet.
+
+### J2 — session lifetime and ordered transport group
+
+- Remove App presentation dependencies from `LiveSessionController`,
+  `LiveSessionHost`, lifecycle host, event router, and command router.
+- Move the same owner instances into Runtime with Core.Net transport and
+  instance-scoped clocks/queues.
+- Preserve bind-before-connect, publish-after-EnterWorld, exact generation
+  rechecks, receive ordering, ack placement, graceful F653/disconnect, and
+  retryable replacement.
+- Let App provide only endpoint credentials, presentation bindings, and
+  graphical lifecycle acknowledgements.
+
+Gate: connected login/logout/reconnect and malformed/reentrant lifecycle suites
+produce the same packet/order trace; no-window construction can connect and
+disconnect without loading App or a backend.
+
+### J3 — canonical identity, properties, and object-table group
+
+- Strip renderer, particle, Wb, and streaming components from the canonical
+  record into an App projection store keyed only by local identity/incarnation.
+- Move `LiveEntityRuntime`, accepted spawn/state/property timestamps,
+  `ClientObjectTable`, container/inventory indices, vitals, enchantments,
+  spell state, target/combat state, and their exact teardown into Runtime.
+- Emit ordered create/update/rebucket/hidden/withdraw/delete deltas.
+- Keep DAT-backed visual hydration, render registrations, effects, lights,
+  paperdoll, selection markers, and radar projections in App.
+
+Gate: GUID reuse, equal-generation updates, parent/child identity,
+inventory/container mutations, Hidden, delete/recreate, and portal teardown
+match current traces; App has no server-GUID ownership.
+
+### J4 — chat, inventory, magic, and gameplay-state services
+
+- Move canonical chat history/channel state, inventory transactions, spell and
+  component state, enchantments, vitals, skills/attributes, and gameplay
+  cooldown state by coherent owner groups.
+- Keep retained panel layout, text shaping, icons, paperdoll rendering, and
+  status-bar presentation in App.
+- Route plugins and future bots through the same typed command/event surface
+  as graphical UI.
+
+Gate: deterministic command/response traces and graphical ViewModel revisions
+match; no Runtime type references UI abstractions.
+
+### J5 — movement, physics, interaction, and combat group
+
+- Move presentation-free movement interpretation, authoritative/predicted
+  physics state, selection identity, approach/use transactions, combat intent,
+  projectiles, and outbound movement cadence.
+- Replace input and camera dependencies with typed commands and runtime views.
+- Keep camera, mouse look, selection markers/highlight, combat/spell bars,
+  animated pose composition, sounds, and particles in App.
+- Share immutable flat collision content while retaining per-session transition
+  scratch.
+
+Gate: bit-identical collision/trajectory fixtures, target-facing and
+auto-approach traces, outbound packet timing, combat/magic commands, and
+graphical feel gates remain unchanged.
+
+### J6 — world, portal, environment, and projection handshake
+
+- Move authoritative teleport/session cell identity, world clock, weather
+  state, and reveal-generation state required by gameplay.
+- Keep streaming publication, terrain/EnvCell rendering, portal tunnel,
+  materialization VFX, sky drawing, audio, and UI in App.
+- Define the destination-ready/withdrawal acknowledgements between Runtime and
+  the graphical or headless host without making visual readiness gameplay
+  authority.
+
+Gate: fresh login, repeated recall/portal, world edge, dungeon, reconnect, and
+mid-portal disconnect traces match; the graphical screenshots remain accepted.
+
+### J7 — one `GameRuntime` composition root
+
+- Compose all moved lifetime groups into one instance-scoped `GameRuntime`.
+- Make `GameWindow`/App own exactly one Runtime instance plus presentation
+  adapters.
+- Delete temporary direct-owner adapters and every superseded App production
+  path.
+- Register all Runtime and App projection owners with structural acquisition
+  leases and the exact teardown transaction.
+
+Gate: graphical connected lifecycle/resource routes pass with no mirrored
+state, no extra update latency, and no performance regression.
+
+### J8 — no-window integration and Slice J closeout
+
+- Build a transport/content test host that constructs Runtime directly.
+- Connect, enter world, receive chat/inventory/world updates, move, use,
+  fight/cast through deterministic fixtures, portal, log out, reconnect, and
+  tear down without loading App/Silk/OpenAL/UI.
+- Add cancellation, failure injection, same-process multiple-instance
+  isolation, credential-safe diagnostics, and zero-presentation-allocation
+  gates.
+- Update architecture, milestone, roadmap, issue/divergence ledgers, and
+  durable memory.
+
+Final gate: Release build/full tests, connected graphical route, no-window
+integration, resource teardown, packet/order/timing parity, and the user visual
+matrix all pass. Slice K may then build the Linux multi-session host without
+another gameplay extraction.
+
+## 5. Commit order
+
+1. `arch(runtime): establish presentation-independent boundary`
+2. `feat(runtime): define borrowed views commands and ordered events`
+3. `refactor(runtime): move session lifetime and ordered transport`
+4. `refactor(runtime): move canonical entity and property ownership`
+5. `refactor(runtime): move gameplay state services`
+6. `refactor(runtime): move movement physics interaction and combat`
+7. `refactor(runtime): separate world authority from presentation`
+8. `refactor(runtime): compose one graphical game runtime`
+9. `test(runtime): close no-window parity and teardown`
+
+Each commit is independently buildable and retains an exact rollback command
+in this plan before its connected gate.

src/AcDream.App/AcDream.App.csproj

@@ -39,6 +39,7 @@
     <PackageReference Include="StbTrueTypeSharp" Version="1.26.12" />
   </ItemGroup>
   <ItemGroup>
+    <ProjectReference Include="..\AcDream.Runtime\AcDream.Runtime.csproj" />
     <ProjectReference Include="..\AcDream.Core\AcDream.Core.csproj" />
     <ProjectReference Include="..\AcDream.Core.Net\AcDream.Core.Net.csproj" />
     <ProjectReference Include="..\AcDream.Content\AcDream.Content.csproj" />

src/AcDream.Runtime/AcDream.Runtime.csproj

@@ -0,0 +1,19 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <LangVersion>latest</LangVersion>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+    <RootNamespace>AcDream.Runtime</RootNamespace>
+  </PropertyGroup>
+  <ItemGroup>
+    <InternalsVisibleTo Include="AcDream.Runtime.Tests" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\AcDream.Core\AcDream.Core.csproj" />
+    <ProjectReference Include="..\AcDream.Core.Net\AcDream.Core.Net.csproj" />
+    <ProjectReference Include="..\AcDream.Content\AcDream.Content.csproj" />
+    <ProjectReference Include="..\AcDream.Plugin.Abstractions\AcDream.Plugin.Abstractions.csproj" />
+  </ItemGroup>
+</Project>

src/AcDream.Runtime/RuntimeAssemblyMarker.cs

@@ -0,0 +1,10 @@
+namespace AcDream.Runtime;
+
+/// <summary>
+/// Identifies the presentation-independent runtime assembly.
+/// </summary>
+/// <remarks>
+/// Slice J0 establishes only the dependency boundary. Runtime owners move here
+/// in coherent lifetime groups during the later Slice J steps.
+/// </remarks>
+internal static class RuntimeAssemblyMarker;

tests/AcDream.Runtime.Tests/AcDream.Runtime.Tests.csproj

@@ -0,0 +1,22 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <IsPackable>false</IsPackable>
+    <LangVersion>latest</LangVersion>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+  </PropertyGroup>
+  <ItemGroup>
+    <PackageReference Include="coverlet.collector" Version="6.0.4" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.14.1" />
+    <PackageReference Include="xunit" Version="2.9.3" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="3.1.4" />
+  </ItemGroup>
+  <ItemGroup>
+    <Using Include="Xunit" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\AcDream.Runtime\AcDream.Runtime.csproj" />
+  </ItemGroup>
+</Project>

tests/AcDream.Runtime.Tests/RuntimeDependencyBoundaryTests.cs

@@ -0,0 +1,127 @@
+using System.Text.Json;
+using System.Xml.Linq;
+
+namespace AcDream.Runtime.Tests;
+
+public sealed class RuntimeDependencyBoundaryTests
+{
+    private static readonly string[] ForbiddenDependencyPrefixes =
+    [
+        "AcDream.App",
+        "AcDream.UI.",
+        "Silk.NET",
+        "OpenAL",
+        "Arch",
+        "ImGui",
+    ];
+
+    [Fact]
+    public void RuntimeAssemblyHasNoDirectPresentationOrBackendReferences()
+    {
+        var references = typeof(RuntimeAssemblyMarker).Assembly
+            .GetReferencedAssemblies()
+            .Select(static reference => reference.Name ?? string.Empty)
+            .ToArray();
+
+        Assert.DoesNotContain(references, IsForbidden);
+    }
+
+    [Fact]
+    public void RuntimeDependencyClosureHasNoPresentationOrBackendLibraries()
+    {
+        var depsPath = Path.ChangeExtension(
+            typeof(RuntimeDependencyBoundaryTests).Assembly.Location,
+            ".deps.json");
+
+        using var document = JsonDocument.Parse(File.ReadAllText(depsPath));
+        var libraries = document.RootElement
+            .GetProperty("libraries")
+            .EnumerateObject()
+            .Select(static library => LibraryName(library.Name))
+            .ToArray();
+
+        Assert.DoesNotContain(libraries, IsForbidden);
+    }
+
+    [Fact]
+    public void RuntimeProjectDeclaresOnlyApprovedProjectDependencies()
+    {
+        var repositoryRoot = FindRepositoryRoot();
+        var projectPath = Path.Combine(
+            repositoryRoot,
+            "src",
+            "AcDream.Runtime",
+            "AcDream.Runtime.csproj");
+        var project = XDocument.Load(projectPath);
+        var projectDirectory = Path.GetDirectoryName(projectPath)!;
+
+        var actualReferences = project
+            .Descendants("ProjectReference")
+            .Select(reference => reference.Attribute("Include")?.Value)
+            .Where(static include => !string.IsNullOrWhiteSpace(include))
+            .Select(include => Path.GetFullPath(Path.Combine(projectDirectory, include!)))
+            .Order(StringComparer.OrdinalIgnoreCase)
+            .ToArray();
+        var expectedReferences = new[]
+            {
+                "AcDream.Content",
+                "AcDream.Core",
+                "AcDream.Core.Net",
+                "AcDream.Plugin.Abstractions",
+            }
+            .Select(projectName => Path.Combine(
+                repositoryRoot,
+                "src",
+                projectName,
+                $"{projectName}.csproj"))
+            .Order(StringComparer.OrdinalIgnoreCase)
+            .ToArray();
+
+        Assert.Equal(expectedReferences, actualReferences);
+        Assert.Empty(project.Descendants("PackageReference"));
+    }
+
+    [Fact]
+    public void LoadingRuntimeMarkerDoesNotLoadPresentationOrBackendAssemblies()
+    {
+        _ = typeof(RuntimeAssemblyMarker).Assembly;
+
+        var loadedAssemblies = AppDomain.CurrentDomain
+            .GetAssemblies()
+            .Select(static assembly => assembly.GetName().Name ?? string.Empty)
+            .ToArray();
+
+        Assert.DoesNotContain(loadedAssemblies, IsForbidden);
+    }
+
+    private static string FindRepositoryRoot()
+    {
+        var directory = new DirectoryInfo(AppContext.BaseDirectory);
+        while (directory is not null)
+        {
+            if (File.Exists(Path.Combine(directory.FullName, "AcDream.slnx")))
+            {
+                return directory.FullName;
+            }
+
+            directory = directory.Parent;
+        }
+
+        throw new DirectoryNotFoundException(
+            $"Could not find AcDream.slnx above {AppContext.BaseDirectory}.");
+    }
+
+    private static string LibraryName(string libraryIdentity)
+    {
+        var separatorIndex = libraryIdentity.IndexOf('/');
+        return separatorIndex < 0
+            ? libraryIdentity
+            : libraryIdentity[..separatorIndex];
+    }
+
+    private static bool IsForbidden(string assemblyName)
+    {
+        return ForbiddenDependencyPrefixes.Any(prefix =>
+            assemblyName.StartsWith(prefix, StringComparison.OrdinalIgnoreCase));
+    }
+}