Add editor-only floor cut to hide primitives above the MandatoryAnchor

Per-component visibility/collision toggle gated on bounds-min Z vs
(AnchorZ + Height). Snapshotted before mutation and restored on
disable, so the feature is non-destructive. Wired into the toolbars of
both Slate widgets and exposed as Blueprint methods on the UMG widget.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.claude/memory/MEMORY.md

@@ -1,4 +1,4 @@
-- [PS_Editor plugin project](project_ps_editor.md) — Runtime editor plugin for UE 5.5, Phases 1-4 done, outline material pending
+- [PS_Editor plugin project](project_ps_editor.md) — Runtime editor plugin for UE 5.7 (migrated from 5.5 in April 2026), Phases 1-4 done, outline material pending
 - [Underscore naming](feedback_naming.md) — Always use PS_Editor_ prefix with underscores in file/class names
-- [UE5 build process](reference_build.md) — CLI build command for the project (Build.bat path, target name, flags)
+- [UE5 build process](reference_build.md) — CLI build command for PROSERVE_UE_5_7 (5.5 host deprecated), Build.bat path, target name, junction check
 - [Build workflow](feedback_build_workflow.md) — Prefer Live Coding (Ctrl+Alt+F11) when UE is open, CLI build only when UE is closed

.claude/memory/project_ps_editor.md

@@ -1,10 +1,10 @@
 ---
 name: PS_Editor plugin project
-description: Runtime editor plugin for UE 5.5 - object placement, scene editing, JSON save/load in packaged builds
+description: Runtime editor plugin for UE 5.7 - object placement, scene editing, JSON save/load in packaged builds
 type: project
 ---
 
-PS_Editor is a runtime editor plugin for Unreal Engine 5.5 for the PROSERVE project.
+PS_Editor is a runtime editor plugin for Unreal Engine 5.7 for the PROSERVE project. The plugin was started on UE 5.5; the host project migrated to UE 5.7 in April 2026 and the plugin follows. Build details in reference_build.md.
 
 Key decisions:
 - UI: UMG driven by C++ (Slate)

.claude/memory/reference_build.md

@@ -1,18 +1,30 @@
 ---
 name: UE5 build process
-description: How to build the PS_ProserveEditor UE 5.5 project from command line on Windows
+description: How to build the PROSERVE host project (currently UE 5.7) from command line on Windows
 type: reference
 ---
 
-UE 5.5 is installed at `C:\Program Files\Epic Games\UE_5.5` (found via registry key `HKLM\SOFTWARE\EpicGames\Unreal Engine\5.5`).
+The PS_Editor plugin is developed in `E:\ASTERION\GIT\PS_Editor\Unreal\Plugins\PS_Editor` and consumed by the PROSERVE host project via an NTFS junction. Always build the host project, not the plugin in isolation.
+
+**Current host project (April 2026):** `E:\ASTERION\SVN\DEV\PROSERVE_UE_5_7\PROSERVE_UE_5_7.uproject` (Unreal Engine 5.7)
+
+The previous 5.5 host (`PROSERVE_UE_5_5`) is deprecated — do not use unless explicitly asked.
+
+UE 5.7 is installed at `C:\Program Files\Epic Games\UE_5.7` (found via registry key `HKLM\SOFTWARE\EpicGames\Unreal Engine\5.7`).
 
 Build command (Editor target, Development):
 ```
-"C:/Program Files/Epic Games/UE_5.5/Engine/Build/BatchFiles/Build.bat" PS_ProserveEditorEditor Win64 Development -Project="C:/ASTERION/GIT/PS_ProserveEditor/Unreal/PS_ProserveEditor.uproject" -WaitMutex -FromMsBuild
+"C:/Program Files/Epic Games/UE_5.7/Engine/Build/BatchFiles/Build.bat" PROSERVE_UE_5_7Editor Win64 Development -Project="E:/ASTERION/SVN/DEV/PROSERVE_UE_5_7/PROSERVE_UE_5_7.uproject" -WaitMutex -FromMsBuild
 ```
 
-**How to apply:** Use this command to compile after code changes. Timeout should be set to 600000ms (10 min) for safety. The target name is `PS_ProserveEditorEditor` (Editor suffix) for editor builds.
+**How to apply:** Use this command to compile after code changes. Timeout should be set to 600000ms (10 min) for safety. The target name is `PROSERVE_UE_5_7Editor` (Editor suffix) for editor builds.
 
 **When to use CLI vs Live Coding:**
 - Live Coding (Ctrl+Alt+F11): .cpp only changes (no new UCLASS, USTRUCT, UENUM, UPROPERTY in headers)
 - Full CLI build (UE must be closed): new files, header changes with new reflected types, Build.cs changes
+
+**Plugin junction verification:**
+```
+ls -la E:/ASTERION/SVN/DEV/PROSERVE_UE_5_7/Plugins/ | grep PS_Editor
+```
+Should show a symlink pointing to `/e/ASTERION/GIT/PS_Editor/Unreal/Plugins/PS_Editor`. If broken, the host project will build against a stale or missing plugin copy.

CLAUDE.md

@@ -1,7 +1,7 @@
 # PS_ProserveEditor - Project Guidelines
 
 ## Project Overview
-Unreal Engine 5.5 project with runtime editor plugin (PS_Editor). The plugin enables runtime scene editing in packaged builds: object placement, property editing, scenario definition, splines, lighting, and JSON scene save/load.
+Unreal Engine 5.7 project with runtime editor plugin (PS_Editor). The plugin enables runtime scene editing in packaged builds: object placement, property editing, scenario definition, splines, lighting, and JSON scene save/load. The plugin was started on UE 5.5; the host project migrated to UE 5.7 in April 2026.
 
 ## Architecture
 - **Plugin**: PS_Editor (runtime plugin, must work in packaged builds)
@@ -10,6 +10,91 @@ Unreal Engine 5.5 project with runtime editor plugin (PS_Editor). The plugin ena
 - **Serialization**: JSON via Json/JsonUtilities modules (FJsonObjectConverter)
 - **Input**: Enhanced Input system (AZERTY: arrows + A/Q movement, E/R/T modes)
 
+## Editor vs. Gameplay execution boundary — CRITICAL
+
+The plugin runs in two distinct modes and it's essential never to leak editor-only code
+into the gameplay runtime loaded via `UPS_Editor_SceneLoader::LoadScene` (standalone).
+
+### Editor runtime mode
+Activated when the `APS_Editor_PlayerController` + `APS_Editor_HUD` + `UPS_Editor_MainWidget*`
+stack is created (typical during authoring — the user is in the runtime editor).
+- `UPS_Editor_SceneLoader::bIsEditorModeActive == true`
+- The HUD widget drives property editing, catalogue spawn, save/load, simulate, timeline
+- Interface methods called **only** by the widget (never in gameplay):
+  - `GetCustomOptionsForProperty` / `GetCustomOptionsWithValuesForProperty` / `GetCurrentDisplayForProperty`
+  - `OnEditorModeChanged`, `OnEditorTick`
+  - `OnEditorNeedsReinit`, `OnEditorNeedsRespawn`
+
+### Gameplay mode
+The project (PROSERVE) loads a scenario via `UPS_Editor_SceneLoader::LoadScene` from a GameMode
+BeginPlay, without ever instantiating the editor PlayerController / HUD / widget.
+- `UPS_Editor_SceneLoader::bIsEditorModeActive == false`
+- Actors spawn, their properties are applied from JSON, `OnPropertiesLoaded` fires once
+- The timeline subsystem auto-plays if the scenario has tracks, driven **server-side only**
+
+### Interface methods that fire in BOTH modes
+- `OnPropertiesLoaded` — after every scene load, editor or gameplay (applied once post-spawn)
+- `OnEditorPropertyChanged` — fires both in editor (on UI edit via `ApplyPropertyFromUI`) AND
+  in gameplay (on server when the timeline applies a new keyframe value via
+  `TimelineSubsystem::ApplyTrackAtTime`). Despite the name, the "Editor" refers to the
+  PS_Editor plugin — the event is the canonical hook for "a property changed at runtime".
+  In gameplay only the **server** invokes it; client-side reaction must go through
+  `ReplicatedUsing=OnRep_X` RepNotify on the replicated property.
+
+### Rule when adding new features
+- Anything tied to property panel UI (new interface method, new widget logic, dropdown
+  helpers, etc.) lives in the widget only — no extra work to scope it out of gameplay
+- Anything added to the `SceneLoader::LoadScene` path runs in gameplay and must handle
+  `NM_Client`, replication, and server-authority correctly (the timeline subsystem is the
+  reference pattern)
+- Expensive BP implementations of editor-UI interface methods (DataTable lookups, class
+  resolution, etc.) can stay expensive — they never run outside the authoring session
+
+### How to guard code that could run in either mode
+```cpp
+if (UPS_Editor_SceneLoader::IsInEditorMode())
+{
+    // editor-only behaviour
+}
+```
+
+### Known PIE-only AI quirk — use Standalone for AI testing
+
+When the editor's "Play" button calls `UGameplayStatics::OpenLevel(BaseLevel)` from a PIE
+session, the BaseLevel's `RecastNavMesh` actor ends up pending-kill at registration time
+(UE logs `RegistrationFailed_DataPendingKill` ×2 and silently spawns an empty
+`AbstractNavData-Default` as fallback). All `FindPathAsync` / `ProjectPointToNavigation`
+queries return empty after that — pathfinding looks broken with no error.
+
+This is **PIE-specific**:
+- Standalone Game (Window → Standalone) — works correctly
+- Packaged builds — work correctly
+- PIE direct on BaseLevel (no editor map / OpenLevel involved) — works correctly
+- PIE on editor map → click Play (OpenLevel transition inside PIE) — broken
+
+Multiple workaround attempts have all failed (cascading re-registrations through
+`RegisterNavData` / `OnInitializeActors` / `AddNavigationSystemToWorld` / `Build` /
+`SpawnMissingNavigationData`; transition map; duplicated sublevel suffixed `_default`).
+The cause is internal to PIE's OpenLevel handling and cannot be fixed from the plugin
+side without engine modifications.
+
+**Workflow:** for AI iteration, run **Standalone Game** instead of PIE. It exercises the
+exact same code path as packaged builds.
+or gate on `bIsCurrentlyLoading` to skip BP init during JSON restore.
+
+## UI Modes — IMPORTANT for widget changes
+
+The runtime editor ships with **multiple widget implementations** that must all stay in sync:
+- `PS_Editor_MainWidget.cpp/.h` — modern UMG-based widget (primary target long-term)
+- `PS_Editor_MainWidget_Legacy.cpp/.h` — Slate-only legacy widget (**currently active** as of April 2026)
+- `PS_Editor_MainWidget_UMG.cpp/.h` — UMG variant
+
+The user can switch between them via a `UIMode` setting. At any given time only one is running, but the project keeps all three compiled.
+
+**Rule:** when changing any behavior inside a widget (new interface calls, new property row logic, new UI controls, bug fixes in RebuildDynamicProperties / ApplyPropertyFromUI / RefreshDynamicPropertyValues, etc.), **apply the change to ALL widget implementations at the same time**. Otherwise the user's current UIMode gets the fix and the others don't — the "it's like you didn't change anything" bug.
+
+Symptom that the wrong widget was edited: logs you added don't appear in the Output Log despite the build being clean and the DLL being correctly loaded. Always grep for the function name across all `PS_Editor_MainWidget*.cpp` files before assuming a single edit is sufficient.
+
 ## Naming Conventions
 - All plugin files and classes use the `PS_Editor_` prefix (e.g., `PS_Editor_GameMode`, `PS_Editor_Pawn`)
 - Code and comments in English
@@ -21,15 +106,28 @@ Unreal Engine 5.5 project with runtime editor plugin (PS_Editor). The plugin ena
 - When fixing a bug, fix the root cause, not the symptom.
 - If something requires error handling or validation to work reliably, include it without asking.
 
+## Workflow — CRITICAL
+- **Do not make behavior / logic changes without first explaining the plan and waiting for the
+  user's go-ahead.** Explain what the change will be, why it fixes the issue, and what side
+  effects it could have. Only after the user approves (or asks to proceed), apply the edit.
+- Diagnostic-only additions (temporary `UE_LOG`, read-only inspections) are fine without
+  approval because they can't regress the project.
+- Refactors, algorithm changes, comportement changes, new defaults, removed features — all
+  require approval first, even when they seem obvious.
+- When revealing new data (e.g. logs) suggests a fix, STATE the proposed fix in plain words
+  and wait. Don't pre-emptively write + apply the code change in the same turn.
+
 ## Build
-- Engine: Unreal Engine 5.5
-- Plugin location: `Unreal/Plugins/PS_Editor/`
-- Game module: `PS_ProserveEditor` (in `Unreal/Source/PS_ProserveEditor/`)
+- Engine: Unreal Engine 5.7 (host project migrated from 5.5 in April 2026)
+- Plugin location: `Unreal/Plugins/PS_Editor/` (consumed via NTFS junction from the PROSERVE host project's `Plugins/` directory)
+- Host project: `E:\ASTERION\SVN\DEV\PROSERVE_UE_5_7\PROSERVE_UE_5_7.uproject` — always build this, not the plugin in isolation
+- Game module: `PROSERVE_UE_5_7` (in the host project's `Source/`)
 - CLI build command (Editor, Development):
   ```
-  "<UE_INSTALL>/Engine/Build/BatchFiles/Build.bat" PS_ProserveEditorEditor Win64 Development -Project="<REPO>/Unreal/PS_ProserveEditor.uproject" -WaitMutex -FromMsBuild
+  "C:/Program Files/Epic Games/UE_5.7/Engine/Build/BatchFiles/Build.bat" PROSERVE_UE_5_7Editor Win64 Development -Project="E:/ASTERION/SVN/DEV/PROSERVE_UE_5_7/PROSERVE_UE_5_7.uproject" -WaitMutex -FromMsBuild
   ```
-  UE install path can be found via registry: `HKLM\SOFTWARE\EpicGames\Unreal Engine\5.5` > `InstalledDirectory`
+  UE install path can be found via registry: `HKLM\SOFTWARE\EpicGames\Unreal Engine\5.7` > `InstalledDirectory`
+- The 5.5 host (`PROSERVE_UE_5_5`) is deprecated — do not build against it unless explicitly asked.
 
 ## Project Memory
 Shared project memory is stored in `.claude/memory/` (versioned in the repository). When starting a new session on any machine, read these files to restore context: