diff --git a/AGENTS.md b/AGENTS.md
index fa25fe60..dd7f5549 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -45,13 +45,14 @@ in `src/AcDream.*` references it as a project dependency.
   `TextureCache`, `GlobalMeshBuffer`, shader infrastructure, and the
   EnvCell/portal/scenery/terrain-blending pipeline classes.
 
-**Modern rendering path is MANDATORY** as of the N.5 ship amendment.
-`WbFoundationFlag`, `InstancedMeshRenderer`, and `StaticMeshRenderer`
-are deleted. Missing `GL_ARB_bindless_texture` or
-`GL_ARB_shader_draw_parameters` throws `NotSupportedException` at
-startup. There is no legacy fallback. Engineering cribs (WbMeshAdapter
-seams, N.5 SSBO layout, translucency model, gotchas) live in
-`memory/reference_modern_rendering_pipeline.md`.
+**Modern rendering path is MANDATORY.** The N.5 ship amendment deleted
+`WbFoundationFlag`, `InstancedMeshRenderer`, and `StaticMeshRenderer`;
+Campaign V (`docs/plans/2026-07-27-vulkan-campaign.md`, closed
+2026-07-29) then ported the renderer to Vulkan behind the RHI contract
+and deleted the OpenGL backend outright — `AcDream.App` references only
+`Silk.NET.Vulkan`. There is no legacy fallback. Engineering cribs
+(WbMeshAdapter seams, N.5 SSBO layout, translucency model, gotchas)
+live in `memory/reference_modern_rendering_pipeline.md`.
 
 Before re-implementing any AC-specific rendering or dat-handling
 algorithm, **read `docs/architecture/worldbuilder-inventory.md` FIRST**.
@@ -78,17 +79,20 @@ and `~/.claude/projects/.../memory/` (the latter is browsable in
 Obsidian via the `claude-memory/` junction in the repo root; see
 `memory/reference_obsidian_vault.md`).
 
-**UI strategy:** two coexisting presentation stacks over shared state,
-ViewModels, events, and commands. ImGui.NET +
-`Silk.NET.OpenGL.Extensions.ImGui` is the permanent
-`ACDREAM_DEVTOOLS=1` developer stack using `IPanel`/`IPanelRenderer`.
-Retail gameplay UI is the independent retained `UiHost`/`UiRoot` tree in
-`AcDream.App/UI`, imported from LayoutDesc/DAT assets and bound by focused
-controllers. The stable cross-stack seam is ViewModels/commands, not a backend
-swap. `TextRenderer` + `BitmapFont` also serve D.6 world-space HUD elements
-where ImGui cannot reach the 3D scene. Plugin gameplay UI uses the BCL-only
+**UI strategy:** one presentation stack — the retained retail
+`UiHost`/`UiRoot` tree in `AcDream.App/UI`, imported from LayoutDesc/DAT
+assets and bound by focused controllers over shared state, ViewModels,
+events, and commands (the ViewModels/commands seam from the earlier
+two-stack era remains the stable boundary between state and
+presentation). The ImGui.NET developer-tools frontend
+(`AcDream.UI.ImGui`) and the OpenGL backend it required were deleted at
+Campaign V slice V11 (`docs/plans/2026-07-27-vulkan-campaign.md`);
+`ACDREAM_DEVTOOLS=1` now only selects the optional Vulkan
+validation/debug-utils extensions (see the flag's log line in
+`Program.cs`). `TextRenderer` + `BitmapFont` serve D.6 world-space HUD
+elements in the 3D scene. Plugin gameplay UI uses the BCL-only
 `AcDream.Plugin.Abstractions.IUiRegistry.AddMarkupPanel` contract; plugins
-never import App or ImGui namespaces. Full design:
+never import App namespaces. Full design:
 [`docs/plans/2026-04-24-ui-framework.md`](docs/plans/2026-04-24-ui-framework.md).
 Memory cribs: `claude-memory/project_chat_pipeline.md` (chat pipeline as of
 Phase I), `claude-memory/project_input_pipeline.md` (input pipeline as of
diff --git a/CLAUDE.md b/CLAUDE.md
index 10ff8c2d..11e4a643 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -43,13 +43,14 @@ in `src/AcDream.*` references it as a project dependency.
   `TextureCache`, `GlobalMeshBuffer`, shader infrastructure, and the
   EnvCell/portal/scenery/terrain-blending pipeline classes.
 
-**Modern rendering path is MANDATORY** as of the N.5 ship amendment.
-`WbFoundationFlag`, `InstancedMeshRenderer`, and `StaticMeshRenderer`
-are deleted. Missing `GL_ARB_bindless_texture` or
-`GL_ARB_shader_draw_parameters` throws `NotSupportedException` at
-startup. There is no legacy fallback. Engineering cribs (WbMeshAdapter
-seams, N.5 SSBO layout, translucency model, gotchas) live in
-`memory/reference_modern_rendering_pipeline.md`.
+**Modern rendering path is MANDATORY.** The N.5 ship amendment deleted
+`WbFoundationFlag`, `InstancedMeshRenderer`, and `StaticMeshRenderer`;
+Campaign V (`docs/plans/2026-07-27-vulkan-campaign.md`, closed
+2026-07-29) then ported the renderer to Vulkan behind the RHI contract
+and deleted the OpenGL backend outright — `AcDream.App` references only
+`Silk.NET.Vulkan`. There is no legacy fallback. Engineering cribs
+(WbMeshAdapter seams, N.5 SSBO layout, translucency model, gotchas)
+live in `memory/reference_modern_rendering_pipeline.md`.
 
 Before re-implementing any AC-specific rendering or dat-handling
 algorithm, **read `docs/architecture/worldbuilder-inventory.md` FIRST**.
@@ -76,17 +77,20 @@ and `~/.claude/projects/.../memory/` (the latter is browsable in
 Obsidian via the `claude-memory/` junction in the repo root; see
 `memory/reference_obsidian_vault.md`).
 
-**UI strategy:** two coexisting presentation stacks over shared state,
-ViewModels, events, and commands. ImGui.NET +
-`Silk.NET.OpenGL.Extensions.ImGui` is the permanent
-`ACDREAM_DEVTOOLS=1` developer stack using `IPanel`/`IPanelRenderer`.
-Retail gameplay UI is the independent retained `UiHost`/`UiRoot` tree in
-`AcDream.App/UI`, imported from LayoutDesc/DAT assets and bound by focused
-controllers. The stable cross-stack seam is ViewModels/commands, not a backend
-swap. `TextRenderer` + `BitmapFont` also serve D.6 world-space HUD elements
-where ImGui cannot reach the 3D scene. Plugin gameplay UI uses the BCL-only
+**UI strategy:** one presentation stack — the retained retail
+`UiHost`/`UiRoot` tree in `AcDream.App/UI`, imported from LayoutDesc/DAT
+assets and bound by focused controllers over shared state, ViewModels,
+events, and commands (the ViewModels/commands seam from the earlier
+two-stack era remains the stable boundary between state and
+presentation). The ImGui.NET developer-tools frontend
+(`AcDream.UI.ImGui`) and the OpenGL backend it required were deleted at
+Campaign V slice V11 (`docs/plans/2026-07-27-vulkan-campaign.md`);
+`ACDREAM_DEVTOOLS=1` now only selects the optional Vulkan
+validation/debug-utils extensions (see the flag's log line in
+`Program.cs`). `TextRenderer` + `BitmapFont` serve D.6 world-space HUD
+elements in the 3D scene. Plugin gameplay UI uses the BCL-only
 `AcDream.Plugin.Abstractions.IUiRegistry.AddMarkupPanel` contract; plugins
-never import App or ImGui namespaces. Full design:
+never import App namespaces. Full design:
 [`docs/plans/2026-04-24-ui-framework.md`](docs/plans/2026-04-24-ui-framework.md).
 Memory cribs: `claude-memory/project_chat_pipeline.md` (chat pipeline as of
 Phase I), `claude-memory/project_input_pipeline.md` (input pipeline as of