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+# Indoor Cell Rendering Fix — Phase 1 Diagnostics Implementation Plan
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Add five toggleable diagnostic probes that pinpoint where the EnvCell rendering chain breaks, so Phase 2's fix can target the actual failure point.
+
+**Architecture:** Single `RenderingDiagnostics` static class in `AcDream.Core.Rendering` exposes five bool flags + a master toggle (env-var-initialized, runtime-settable). DebugVM mirrors them as live-toggle properties; DebugPanel exposes them as checkboxes. Probe call sites in `WbMeshAdapter` and `WbDrawDispatcher` emit one structured `[indoor-*]` line per event when the corresponding flag is on. The Holtburg Inn floor-missing bug is the test case — log output identifies which of six hypotheses (H1–H6 in the spec) the failure matches.
+
+**Tech Stack:** C# .NET 10, xUnit (test framework), Silk.NET OpenGL (rendering), Chorizite.OpenGLSDLBackend (WB ObjectMeshManager).
+
+**Spec:** [`docs/superpowers/specs/2026-05-19-indoor-cell-rendering-fix-design.md`](../specs/2026-05-19-indoor-cell-rendering-fix-design.md)
+
+---
+
+## File Structure
+
+| File | Status | Responsibility |
+|---|---|---|
+| `src/AcDream.Core/Rendering/RenderingDiagnostics.cs` | NEW | Static class with five `bool` properties + master toggle. Env-var read at startup; runtime-settable. |
+| `tests/AcDream.Core.Tests/Rendering/RenderingDiagnosticsTests.cs` | NEW | Verify default values and get/set behavior of the diagnostic flags. |
+| `src/AcDream.UI.Abstractions/Panels/Debug/DebugVM.cs` | MODIFY | Add five mirror properties that forward to `RenderingDiagnostics`. |
+| `src/AcDream.UI.Abstractions/Panels/Debug/DebugPanel.cs` | MODIFY | Add an "Indoor rendering" subsection in `DrawDiagnostics` with six checkboxes. |
+| `src/AcDream.App/Rendering/Wb/WbMeshAdapter.cs` | MODIFY | Emit `[indoor-upload] requested` on first `IncrementRefCount` for an EnvCell id; emit `[indoor-upload] completed` in `Tick()` when WB's staged drain produces that id's `ObjectMeshData`. |
+| `src/AcDream.App/Rendering/Wb/WbDrawDispatcher.cs` | MODIFY | Emit `[indoor-walk]` + `[indoor-cull]` in `WalkVisibleEntities` per cell entity; emit `[indoor-lookup]` and `[indoor-xform]` in `DrawAccumulated` per cell-entity render-data lookup + composed transform. |
+
+---
+
+## Task 1: Create `RenderingDiagnostics` static class
+
+**Files:**
+- Create: `src/AcDream.Core/Rendering/RenderingDiagnostics.cs`
+
+- [ ] **Step 1: Write the file**
+
+The class mirrors `AcDream.Core.Physics.PhysicsDiagnostics` exactly — same env-var-init pattern, same get/set, same XML comments style. Five individual probe flags + one `IndoorAll` master. The master setter cascades to all five.
+
+```csharp
+using System;
+
+namespace AcDream.Core.Rendering;
+
+///
+/// 2026-05-19 — runtime-toggleable diagnostic flags for the indoor cell
+/// rendering pipeline. Initialized from env vars at process start;
+/// flippable at runtime via the DebugPanel mirror. Log call sites read
+/// these statics so a checkbox toggle takes effect on the next frame
+/// without relaunching.
+///
+///
+/// Mirrors the L.2a
+/// pattern. The master toggle is the user's
+/// common case — flipping it cascades to all five probe flags.
+///
+///
+///
+/// Spec: docs/superpowers/specs/2026-05-19-indoor-cell-rendering-fix-design.md.
+///
+///
+public static class RenderingDiagnostics
+{
+ ///
+ /// When true, WbDrawDispatcher.WalkVisibleEntities emits one
+ /// [indoor-walk] line per visible cell entity per second:
+ /// entity id, world position, parent cell id, landblock visible flag,
+ /// AABB-visible flag, "in visible cells" flag, drew flag.
+ /// Initial state from ACDREAM_PROBE_INDOOR_WALK=1.
+ ///
+ public static bool ProbeIndoorWalkEnabled { get; set; } =
+ Environment.GetEnvironmentVariable("ACDREAM_PROBE_INDOOR_WALK") == "1"
+ || Environment.GetEnvironmentVariable("ACDREAM_PROBE_INDOOR_ALL") == "1";
+
+ ///
+ /// When true, WbDrawDispatcher emits one [indoor-lookup]
+ /// line per visible cell entity per second: render-data hit/miss,
+ /// IsSetup flag, SetupParts count, parts-hit / parts-miss tallies.
+ /// Initial state from ACDREAM_PROBE_INDOOR_LOOKUP=1.
+ ///
+ public static bool ProbeIndoorLookupEnabled { get; set; } =
+ Environment.GetEnvironmentVariable("ACDREAM_PROBE_INDOOR_LOOKUP") == "1"
+ || Environment.GetEnvironmentVariable("ACDREAM_PROBE_INDOOR_ALL") == "1";
+
+ ///
+ /// When true, WbMeshAdapter emits two lines per EnvCell id:
+ /// [indoor-upload] requested on first IncrementRefCount and
+ /// [indoor-upload] completed when WB's staged drain produces
+ /// its ObjectMeshData. Missing "completed" lines indicate WB
+ /// silently returned null (hypothesis H1).
+ /// Initial state from ACDREAM_PROBE_INDOOR_UPLOAD=1.
+ ///
+ public static bool ProbeIndoorUploadEnabled { get; set; } =
+ Environment.GetEnvironmentVariable("ACDREAM_PROBE_INDOOR_UPLOAD") == "1"
+ || Environment.GetEnvironmentVariable("ACDREAM_PROBE_INDOOR_ALL") == "1";
+
+ ///
+ /// When true, WbDrawDispatcher emits one [indoor-xform]
+ /// line per visible cell entity per second: cell-geometry SetupPart's
+ /// composed world matrix translation. Disambiguates transform
+ /// double-apply (hypothesis H5).
+ /// Initial state from ACDREAM_PROBE_INDOOR_XFORM=1.
+ ///
+ public static bool ProbeIndoorXformEnabled { get; set; } =
+ Environment.GetEnvironmentVariable("ACDREAM_PROBE_INDOOR_XFORM") == "1"
+ || Environment.GetEnvironmentVariable("ACDREAM_PROBE_INDOOR_ALL") == "1";
+
+ ///
+ /// When true, WbDrawDispatcher.WalkVisibleEntities emits one
+ /// [indoor-cull] line per cell entity that gets culled, with
+ /// the reason (visibleCellIds-miss, frustum, landblock). Disambiguates
+ /// cull bugs (hypothesis H3).
+ /// Initial state from ACDREAM_PROBE_INDOOR_CULL=1.
+ ///
+ public static bool ProbeIndoorCullEnabled { get; set; } =
+ Environment.GetEnvironmentVariable("ACDREAM_PROBE_INDOOR_CULL") == "1"
+ || Environment.GetEnvironmentVariable("ACDREAM_PROBE_INDOOR_ALL") == "1";
+
+ ///
+ /// Master toggle. Reading reflects the AND of all five flags
+ /// (true only when every probe is on). Writing cascades — setting
+ /// to turns ALL five flags on; setting to
+ /// turns ALL five off.
+ ///
+ public static bool IndoorAll
+ {
+ get => ProbeIndoorWalkEnabled
+ && ProbeIndoorLookupEnabled
+ && ProbeIndoorUploadEnabled
+ && ProbeIndoorXformEnabled
+ && ProbeIndoorCullEnabled;
+ set
+ {
+ ProbeIndoorWalkEnabled = value;
+ ProbeIndoorLookupEnabled = value;
+ ProbeIndoorUploadEnabled = value;
+ ProbeIndoorXformEnabled = value;
+ ProbeIndoorCullEnabled = value;
+ }
+ }
+
+ ///
+ /// Helper for probe call sites. Returns when
+ /// the low 16 bits of are ≥ 0x0100 — the AC
+ /// convention for EnvCell (indoor) cells, as opposed to outdoor cells
+ /// in the 8×8 landblock grid (0x0001–0x0040).
+ ///
+ public static bool IsEnvCellId(ulong id) => (id & 0xFFFFu) >= 0x0100u;
+}
+```
+
+- [ ] **Step 2: Build**
+
+Run: `dotnet build src/AcDream.Core/AcDream.Core.csproj -c Debug`
+Expected: 0 errors, 0 warnings.
+
+- [ ] **Step 3: Commit**
+
+```bash
+git add src/AcDream.Core/Rendering/RenderingDiagnostics.cs
+git commit -m "$(cat <<'EOF'
+feat(diagnostics): RenderingDiagnostics static class for indoor probes
+
+Five toggleable bool flags + master IndoorAll cascade, mirroring the
+L.2a PhysicsDiagnostics pattern. Env vars at startup, runtime-settable
+via DebugPanel mirrors (added next task). Probe call sites and DebugVM
+wiring follow in subsequent tasks.
+
+Spec: docs/superpowers/specs/2026-05-19-indoor-cell-rendering-fix-design.md
+
+Co-Authored-By: Claude Opus 4.7 (1M context)
+EOF
+)"
+```
+
+---
+
+## Task 2: Unit-test `RenderingDiagnostics`
+
+**Files:**
+- Create: `tests/AcDream.Core.Tests/Rendering/RenderingDiagnosticsTests.cs`
+
+- [ ] **Step 1: Write the failing test**
+
+```csharp
+using AcDream.Core.Rendering;
+using Xunit;
+
+namespace AcDream.Core.Tests.Rendering;
+
+public sealed class RenderingDiagnosticsTests
+{
+ [Fact]
+ public void IndoorAll_True_TurnsAllFlagsOn()
+ {
+ // Reset all flags off first to make the test deterministic
+ // regardless of env-var state on the test runner.
+ RenderingDiagnostics.ProbeIndoorWalkEnabled = false;
+ RenderingDiagnostics.ProbeIndoorLookupEnabled = false;
+ RenderingDiagnostics.ProbeIndoorUploadEnabled = false;
+ RenderingDiagnostics.ProbeIndoorXformEnabled = false;
+ RenderingDiagnostics.ProbeIndoorCullEnabled = false;
+
+ RenderingDiagnostics.IndoorAll = true;
+
+ Assert.True(RenderingDiagnostics.ProbeIndoorWalkEnabled);
+ Assert.True(RenderingDiagnostics.ProbeIndoorLookupEnabled);
+ Assert.True(RenderingDiagnostics.ProbeIndoorUploadEnabled);
+ Assert.True(RenderingDiagnostics.ProbeIndoorXformEnabled);
+ Assert.True(RenderingDiagnostics.ProbeIndoorCullEnabled);
+ Assert.True(RenderingDiagnostics.IndoorAll);
+ }
+
+ [Fact]
+ public void IndoorAll_False_TurnsAllFlagsOff()
+ {
+ RenderingDiagnostics.IndoorAll = true; // start from all-on
+ RenderingDiagnostics.IndoorAll = false;
+
+ Assert.False(RenderingDiagnostics.ProbeIndoorWalkEnabled);
+ Assert.False(RenderingDiagnostics.ProbeIndoorLookupEnabled);
+ Assert.False(RenderingDiagnostics.ProbeIndoorUploadEnabled);
+ Assert.False(RenderingDiagnostics.ProbeIndoorXformEnabled);
+ Assert.False(RenderingDiagnostics.ProbeIndoorCullEnabled);
+ Assert.False(RenderingDiagnostics.IndoorAll);
+ }
+
+ [Fact]
+ public void IndoorAll_OneOff_ReadsAsFalse()
+ {
+ RenderingDiagnostics.IndoorAll = true;
+ RenderingDiagnostics.ProbeIndoorCullEnabled = false; // flip one off
+ Assert.False(RenderingDiagnostics.IndoorAll);
+ }
+
+ [Theory]
+ [InlineData(0x00000029ul, false)] // outdoor cell 0x29 in 8x8 grid
+ [InlineData(0xA9B40029ul, false)] // outdoor cell with landblock prefix
+ [InlineData(0x00000100ul, true)] // indoor cell minimum
+ [InlineData(0x00000105ul, true)] // typical Holtburg Inn interior
+ [InlineData(0xA9B40105ul, true)] // indoor with landblock prefix
+ [InlineData(0xA9B401FFul, true)] // indoor near top of range
+ public void IsEnvCellId_DistinguishesOutdoorVsIndoorByLow16Bits(ulong id, bool expected)
+ {
+ Assert.Equal(expected, RenderingDiagnostics.IsEnvCellId(id));
+ }
+}
+```
+
+- [ ] **Step 2: Run tests — expect failure on first build**
+
+Run: `dotnet test tests/AcDream.Core.Tests/AcDream.Core.Tests.csproj --filter "FullyQualifiedName~RenderingDiagnostics" -c Debug --nologo`
+
+Expected: Build green (Task 1 already implemented the class). All 7 tests pass (1 cascade-on + 1 cascade-off + 1 partial-off + 4 IsEnvCellId rows).
+
+If any test fails, the implementation in Task 1 has a bug — go back and fix.
+
+- [ ] **Step 3: Commit**
+
+```bash
+git add tests/AcDream.Core.Tests/Rendering/RenderingDiagnosticsTests.cs
+git commit -m "$(cat <<'EOF'
+test(diagnostics): RenderingDiagnostics cascade + IsEnvCellId rows
+
+Covers the master IndoorAll cascade (both directions) and the IsEnvCellId
+helper's 0x0100 boundary check across outdoor cells, indoor cells, and
+landblock-prefixed forms.
+
+Co-Authored-By: Claude Opus 4.7 (1M context)
+EOF
+)"
+```
+
+---
+
+## Task 3: Mirror `RenderingDiagnostics` into `DebugVM`
+
+**Files:**
+- Modify: `src/AcDream.UI.Abstractions/Panels/Debug/DebugVM.cs`
+
+- [ ] **Step 1: Read DebugVM and find the existing `ProbeBuilding` mirror block**
+
+Find the `ProbeBuilding` property (around line 270) — that's an existing live-mirror to `PhysicsDiagnostics.ProbeBuildingEnabled`. New mirrors go immediately AFTER `ProbeAutoWalk` (next property in the file), in a new clearly-commented block.
+
+- [ ] **Step 2: Add `using AcDream.Core.Rendering;` at the top of `DebugVM.cs`**
+
+If the using statement is already present, skip. Otherwise insert alphabetically after `using AcDream.Core.Physics;`.
+
+- [ ] **Step 3: Append the five mirror properties to the file**
+
+Find the closing brace of the last existing property block (after `ProbeAutoWalk` or the last `Probe*` property). Insert this block before the class's closing brace:
+
+```csharp
+ // ── Indoor rendering diagnostics (2026-05-19) ───────────────────
+ // Mirror RenderingDiagnostics statics so DebugPanel checkbox toggles
+ // take effect on the next render frame without relaunching.
+
+ ///
+ /// Runtime mirror of RenderingDiagnostics.ProbeIndoorWalkEnabled
+ /// (env var ACDREAM_PROBE_INDOOR_WALK).
+ ///
+ public bool ProbeIndoorWalk
+ {
+ get => RenderingDiagnostics.ProbeIndoorWalkEnabled;
+ set => RenderingDiagnostics.ProbeIndoorWalkEnabled = value;
+ }
+
+ ///
+ /// Runtime mirror of RenderingDiagnostics.ProbeIndoorLookupEnabled
+ /// (env var ACDREAM_PROBE_INDOOR_LOOKUP).
+ ///
+ public bool ProbeIndoorLookup
+ {
+ get => RenderingDiagnostics.ProbeIndoorLookupEnabled;
+ set => RenderingDiagnostics.ProbeIndoorLookupEnabled = value;
+ }
+
+ ///
+ /// Runtime mirror of RenderingDiagnostics.ProbeIndoorUploadEnabled
+ /// (env var ACDREAM_PROBE_INDOOR_UPLOAD).
+ ///
+ public bool ProbeIndoorUpload
+ {
+ get => RenderingDiagnostics.ProbeIndoorUploadEnabled;
+ set => RenderingDiagnostics.ProbeIndoorUploadEnabled = value;
+ }
+
+ ///
+ /// Runtime mirror of RenderingDiagnostics.ProbeIndoorXformEnabled
+ /// (env var ACDREAM_PROBE_INDOOR_XFORM).
+ ///
+ public bool ProbeIndoorXform
+ {
+ get => RenderingDiagnostics.ProbeIndoorXformEnabled;
+ set => RenderingDiagnostics.ProbeIndoorXformEnabled = value;
+ }
+
+ ///
+ /// Runtime mirror of RenderingDiagnostics.ProbeIndoorCullEnabled
+ /// (env var ACDREAM_PROBE_INDOOR_CULL).
+ ///
+ public bool ProbeIndoorCull
+ {
+ get => RenderingDiagnostics.ProbeIndoorCullEnabled;
+ set => RenderingDiagnostics.ProbeIndoorCullEnabled = value;
+ }
+
+ ///
+ /// Runtime mirror of RenderingDiagnostics.IndoorAll — toggles all
+ /// five indoor probes together.
+ ///
+ public bool ProbeIndoorAll
+ {
+ get => RenderingDiagnostics.IndoorAll;
+ set => RenderingDiagnostics.IndoorAll = value;
+ }
+```
+
+- [ ] **Step 4: Build**
+
+Run: `dotnet build src/AcDream.UI.Abstractions/AcDream.UI.Abstractions.csproj -c Debug`
+Expected: 0 errors. The `using AcDream.Core.Rendering;` resolves; new properties compile.
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add src/AcDream.UI.Abstractions/Panels/Debug/DebugVM.cs
+git commit -m "$(cat <<'EOF'
+feat(debugvm): mirror RenderingDiagnostics indoor probes
+
+Live-toggle wrappers for the five indoor-rendering probe flags plus the
+ProbeIndoorAll master cascade. Pattern matches existing ProbeResolve /
+ProbeCell / ProbeBuilding / ProbeAutoWalk mirrors so a checkbox flip in
+the DebugPanel takes effect on the next frame.
+
+Co-Authored-By: Claude Opus 4.7 (1M context)
+EOF
+)"
+```
+
+---
+
+## Task 4: Expose probes in `DebugPanel` Diagnostics group
+
+**Files:**
+- Modify: `src/AcDream.UI.Abstractions/Panels/Debug/DebugPanel.cs`
+
+- [ ] **Step 1: Find `DrawDiagnostics(IPanelRenderer r)` method**
+
+Open the file. Find the method at approximately line 226. The existing pattern reads probe values into locals at the top of the method, then conditionally re-assigns through checkboxes. The new indoor probes follow the same shape, appended after the last existing probe checkbox.
+
+- [ ] **Step 2: Read the locals + checkboxes at the bottom of the existing block**
+
+Find the line that says `if (r.Checkbox("Probe auto-walk (ACDREAM_PROBE_AUTOWALK)", ref probeAutoWalk)) _vm.ProbeAutoWalk = probeAutoWalk;` or similar last existing probe checkbox in `DrawDiagnostics`. New checkboxes go immediately AFTER this line, before the method's closing brace.
+
+- [ ] **Step 3: Insert the new checkboxes**
+
+Before the closing brace of `DrawDiagnostics`, insert:
+
+```csharp
+
+ // ── Indoor rendering diagnostics (2026-05-19) ───────────────
+ // Pinpoint where the EnvCell rendering chain breaks for
+ // hypothesis-driven Phase 2 fix. Spec:
+ // docs/superpowers/specs/2026-05-19-indoor-cell-rendering-fix-design.md
+ r.Separator();
+ r.Text("Indoor rendering (envCell):");
+
+ bool probeIndoorAll = _vm.ProbeIndoorAll;
+ bool probeIndoorWalk = _vm.ProbeIndoorWalk;
+ bool probeIndoorLookup = _vm.ProbeIndoorLookup;
+ bool probeIndoorUpload = _vm.ProbeIndoorUpload;
+ bool probeIndoorXform = _vm.ProbeIndoorXform;
+ bool probeIndoorCull = _vm.ProbeIndoorCull;
+
+ if (r.Checkbox("Indoor: ALL (ACDREAM_PROBE_INDOOR_ALL)", ref probeIndoorAll)) _vm.ProbeIndoorAll = probeIndoorAll;
+ if (r.Checkbox("Indoor: walk (ACDREAM_PROBE_INDOOR_WALK)", ref probeIndoorWalk)) _vm.ProbeIndoorWalk = probeIndoorWalk;
+ if (r.Checkbox("Indoor: lookup (ACDREAM_PROBE_INDOOR_LOOKUP)", ref probeIndoorLookup)) _vm.ProbeIndoorLookup = probeIndoorLookup;
+ if (r.Checkbox("Indoor: upload (ACDREAM_PROBE_INDOOR_UPLOAD)", ref probeIndoorUpload)) _vm.ProbeIndoorUpload = probeIndoorUpload;
+ if (r.Checkbox("Indoor: xform (ACDREAM_PROBE_INDOOR_XFORM)", ref probeIndoorXform)) _vm.ProbeIndoorXform = probeIndoorXform;
+ if (r.Checkbox("Indoor: cull (ACDREAM_PROBE_INDOOR_CULL)", ref probeIndoorCull)) _vm.ProbeIndoorCull = probeIndoorCull;
+```
+
+Note: `r.Separator()` and `r.Text(string)` are the existing `IPanelRenderer` API methods used elsewhere in the file. If they don't exist, drop those two lines (the checkboxes still work standalone).
+
+- [ ] **Step 4: Build**
+
+Run: `dotnet build src/AcDream.UI.Abstractions/AcDream.UI.Abstractions.csproj -c Debug`
+Expected: 0 errors.
+
+If `r.Separator()` / `r.Text()` aren't on `IPanelRenderer`, the build will fail. Remove those two lines and re-build.
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add src/AcDream.UI.Abstractions/Panels/Debug/DebugPanel.cs
+git commit -m "$(cat <<'EOF'
+feat(debugpanel): "Indoor rendering" probe checkboxes
+
+Six checkboxes (ALL master + five individual probes) in the existing
+DrawDiagnostics block. Toggling flips the corresponding
+RenderingDiagnostics.Probe* flag live via DebugVM forwarding.
+
+Co-Authored-By: Claude Opus 4.7 (1M context)
+EOF
+)"
+```
+
+---
+
+## Task 5: Instrument `WbMeshAdapter` with `[indoor-upload]` probes
+
+**Files:**
+- Modify: `src/AcDream.App/Rendering/Wb/WbMeshAdapter.cs`
+
+The upload probe has TWO emission points:
+1. `IncrementRefCount` — emits `requested` on the first call for an EnvCell id (gated by the existing `_metadataPopulated.Add(id)` first-call check).
+2. `Tick()` — emits `completed` when WB's `StagedMeshData` drain produces an `ObjectMeshData` whose `ObjectId` is in our pending-EnvCell set.
+
+- [ ] **Step 1: Add the pending-EnvCell tracking field + `using` statement**
+
+Open `src/AcDream.App/Rendering/Wb/WbMeshAdapter.cs`. Add `using AcDream.Core.Rendering;` near the top with the other `using` statements (after `using AcDream.Core.Meshing;`).
+
+Find the field declarations near the top of the class (around line 34 — `_metadataPopulated`). Add immediately after:
+
+```csharp
+ ///
+ /// EnvCell ids we've requested via PrepareMeshDataAsync but not yet
+ /// seen completion for in Tick(). Used by the [indoor-upload] probe
+ /// to log requested + completed pairs. Cleared per completion;
+ /// missing completions after a few seconds indicate WB silently
+ /// returned null (hypothesis H1 in the design spec).
+ ///
+ private readonly HashSet _pendingEnvCellRequests = new();
+```
+
+- [ ] **Step 2: Emit `[indoor-upload] requested` in `IncrementRefCount`**
+
+Find the `IncrementRefCount(ulong id)` method (around line 116). Inside the `if (_metadataPopulated.Add(id))` block, immediately AFTER the `_ = _meshManager.PrepareMeshDataAsync(id, isSetup: false);` line, add:
+
+```csharp
+ // [indoor-upload] requested probe — only for EnvCell ids.
+ if (RenderingDiagnostics.IsEnvCellId(id) && RenderingDiagnostics.ProbeIndoorUploadEnabled)
+ {
+ _pendingEnvCellRequests.Add(id);
+ Console.WriteLine($"[indoor-upload] requested cellId=0x{id:X8}");
+ }
+```
+
+- [ ] **Step 3: Emit `[indoor-upload] completed` in `Tick`**
+
+Find the `Tick()` method (around line 167). Replace the existing drain loop:
+
+```csharp
+ while (_meshManager!.StagedMeshData.TryDequeue(out var meshData))
+ {
+ _meshManager.UploadMeshData(meshData);
+ }
+```
+
+with:
+
+```csharp
+ while (_meshManager!.StagedMeshData.TryDequeue(out var meshData))
+ {
+ // [indoor-upload] completed probe — check BEFORE upload so we
+ // see what WB actually produced (vertex counts, parts) before
+ // any post-upload mutation.
+ bool isPendingEnvCell = RenderingDiagnostics.ProbeIndoorUploadEnabled
+ && _pendingEnvCellRequests.Remove(meshData.ObjectId);
+
+ var renderData = _meshManager.UploadMeshData(meshData);
+
+ if (isPendingEnvCell)
+ {
+ int parts = meshData.SetupParts?.Count ?? 0;
+ bool hasGeom = meshData.EnvCellGeometry is not null;
+ int cellGeomVerts = meshData.EnvCellGeometry?.Vertices?.Length ?? 0;
+ bool uploadOk = renderData is not null;
+ Console.WriteLine(
+ $"[indoor-upload] completed cellId=0x{meshData.ObjectId:X8} " +
+ $"isSetup={meshData.IsSetup} parts={parts} " +
+ $"hasEnvCellGeom={hasGeom} cellGeomVerts={cellGeomVerts} " +
+ $"uploadOk={uploadOk}");
+ }
+ }
+```
+
+- [ ] **Step 4: Build**
+
+Run: `dotnet build src/AcDream.App/AcDream.App.csproj -c Debug`
+Expected: 0 errors.
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add src/AcDream.App/Rendering/Wb/WbMeshAdapter.cs
+git commit -m "$(cat <<'EOF'
+feat(wb): [indoor-upload] probe for EnvCell mesh requests + completions
+
+Instruments WbMeshAdapter at two sites:
+- IncrementRefCount: on first call for an EnvCell id (low 16 bits ≥
+ 0x0100), tag the id in _pendingEnvCellRequests and log
+ [indoor-upload] requested.
+- Tick: when WB's StagedMeshData drains an ObjectMeshData whose
+ ObjectId matches a pending EnvCell, log [indoor-upload] completed
+ with parts count, EnvCellGeometry vertex count, and upload result.
+
+Missing "completed" lines after "requested" identify hypothesis H1
+(WB silently returns null from PrepareEnvCellMeshData).
+
+Co-Authored-By: Claude Opus 4.7 (1M context)
+EOF
+)"
+```
+
+---
+
+## Task 6: Instrument `WbDrawDispatcher` walk + cull probes
+
+**Files:**
+- Modify: `src/AcDream.App/Rendering/Wb/WbDrawDispatcher.cs`
+
+The `WalkVisibleEntities` method (around line 280) does landblock visibility, per-entity AABB cull, and the `visibleCellIds` filter. Cell entities (entities whose `MeshRefs[0].GfxObjId` low-16-bits ≥ 0x0100) need probes at three decision sites: passed-all, culled-by-aabb, culled-by-visibleCellIds.
+
+To rate-limit, maintain a per-cellId last-log frame counter as a class-level field.
+
+- [ ] **Step 1: Add the rate-limit tracking field + `using` statement**
+
+Add `using AcDream.Core.Rendering;` near the top with the other `using` statements (after `using AcDream.Core.Meshing;`).
+
+Find the class field declarations. Add:
+
+```csharp
+ ///
+ /// Per-cell-entity last-log frame number for rate-limiting the
+ /// [indoor-walk] / [indoor-lookup] / [indoor-xform] / [indoor-cull]
+ /// probes. Defaults to 30 frames at 30Hz = 1 sec.
+ ///
+ private readonly Dictionary _lastIndoorProbeFrame = new();
+ private int _indoorProbeFrameCounter;
+ private const int IndoorProbeRateLimitFrames = 30;
+
+ ///
+ /// Returns true at most once per
+ /// frames per cellId. Caller must already have checked that an indoor
+ /// probe flag is enabled.
+ ///
+ private bool ShouldEmitIndoorProbe(ulong cellId)
+ {
+ if (!_lastIndoorProbeFrame.TryGetValue(cellId, out int last)
+ || _indoorProbeFrameCounter - last >= IndoorProbeRateLimitFrames)
+ {
+ _lastIndoorProbeFrame[cellId] = _indoorProbeFrameCounter;
+ return true;
+ }
+ return false;
+ }
+```
+
+- [ ] **Step 2: Bump the frame counter at the top of `Draw(...)`**
+
+Find the `Draw` method (around line 339). At its very top, after the existing `_shader.Use();` line, add:
+
+```csharp
+ _indoorProbeFrameCounter++;
+```
+
+- [ ] **Step 3: Replace the per-entity filter block in `WalkVisibleEntities`**
+
+Find the per-entity loop in `WalkVisibleEntities` (around lines 313-335). The current shape (simplified):
+
+```csharp
+ foreach (var entity in entry.Entities)
+ {
+ if (entity.MeshRefs.Count == 0) continue;
+
+ if (entity.ParentCellId.HasValue && visibleCellIds is not null
+ && !visibleCellIds.Contains(entity.ParentCellId.Value))
+ continue;
+
+ bool isAnimated = animatedEntityIds?.Contains(entity.Id) == true;
+ if (frustum is not null && !isAnimated && entry.LandblockId != neverCullLandblockId)
+ {
+ if (entity.AabbDirty) entity.RefreshAabb();
+ if (!FrustumCuller.IsAabbVisible(frustum.Value, entity.AabbMin, entity.AabbMax))
+ continue;
+ }
+
+ result.EntitiesWalked++;
+ for (int i = 0; i < entity.MeshRefs.Count; i++)
+ scratch.Add((entity, i, entry.LandblockId));
+ }
+```
+
+Replace the entire `foreach (var entity in entry.Entities)` body with this instrumented version:
+
+```csharp
+ foreach (var entity in entry.Entities)
+ {
+ if (entity.MeshRefs.Count == 0) continue;
+
+ // Detect cell entity for indoor probes — first MeshRef.GfxObjId
+ // is an EnvCell id (low 16 bits ≥ 0x0100). Cheap to compute;
+ // result reused for all four probe checks below.
+ ulong cellProbeId = (ulong)entity.MeshRefs[0].GfxObjId;
+ bool isCellEntity = RenderingDiagnostics.IsEnvCellId(cellProbeId);
+
+ bool cellInVis = !(entity.ParentCellId.HasValue
+ && visibleCellIds is not null
+ && !visibleCellIds.Contains(entity.ParentCellId.Value));
+ if (!cellInVis)
+ {
+ if (isCellEntity && RenderingDiagnostics.ProbeIndoorCullEnabled
+ && ShouldEmitIndoorProbe(cellProbeId))
+ {
+ Console.WriteLine(
+ $"[indoor-cull] cellEnt=0x{entity.Id:X8} " +
+ $"reason=visibleCellIds-miss " +
+ $"parentCell=0x{entity.ParentCellId!.Value:X8}");
+ }
+ continue;
+ }
+
+ bool isAnimated = animatedEntityIds?.Contains(entity.Id) == true;
+ bool aabbVisible = true;
+ if (frustum is not null && !isAnimated && entry.LandblockId != neverCullLandblockId)
+ {
+ if (entity.AabbDirty) entity.RefreshAabb();
+ aabbVisible = FrustumCuller.IsAabbVisible(frustum.Value, entity.AabbMin, entity.AabbMax);
+ }
+
+ if (!aabbVisible)
+ {
+ if (isCellEntity && RenderingDiagnostics.ProbeIndoorCullEnabled
+ && ShouldEmitIndoorProbe(cellProbeId))
+ {
+ Console.WriteLine(
+ $"[indoor-cull] cellEnt=0x{entity.Id:X8} " +
+ $"reason=frustum " +
+ $"aabbMin=({entity.AabbMin.X:F1},{entity.AabbMin.Y:F1},{entity.AabbMin.Z:F1}) " +
+ $"aabbMax=({entity.AabbMax.X:F1},{entity.AabbMax.Y:F1},{entity.AabbMax.Z:F1})");
+ }
+ continue;
+ }
+
+ // Passed all filters — emit walk probe.
+ if (isCellEntity && RenderingDiagnostics.ProbeIndoorWalkEnabled
+ && ShouldEmitIndoorProbe(cellProbeId))
+ {
+ Console.WriteLine(
+ $"[indoor-walk] cellEnt=0x{entity.Id:X8} " +
+ $"pos=({entity.Position.X:F1},{entity.Position.Y:F1},{entity.Position.Z:F1}) " +
+ $"parentCell=0x{(entity.ParentCellId ?? 0u):X8} " +
+ $"meshRef0=0x{cellProbeId:X8} " +
+ $"meshRefCount={entity.MeshRefs.Count} " +
+ $"landblockVisible=true aabbVisible=true cellInVis=true");
+ }
+
+ result.EntitiesWalked++;
+ for (int i = 0; i < entity.MeshRefs.Count; i++)
+ scratch.Add((entity, i, entry.LandblockId));
+ }
+```
+
+Important: `ShouldEmitIndoorProbe(cellProbeId)` is intentionally called only once per probe-decision-site per cellId, so each cellId emits at most ONE line per frame across all four probe sites (whichever fires first).
+
+- [ ] **Step 4: Build**
+
+Run: `dotnet build src/AcDream.App/AcDream.App.csproj -c Debug`
+Expected: 0 errors. The `using AcDream.Core.Rendering;` resolves; the new field + helper compile; the instrumented loop builds cleanly.
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add src/AcDream.App/Rendering/Wb/WbDrawDispatcher.cs
+git commit -m "$(cat <<'EOF'
+feat(dispatcher): [indoor-walk] + [indoor-cull] probes
+
+Instruments WalkVisibleEntities to identify whether cell entities (first
+MeshRef.GfxObjId low-16-bits ≥ 0x0100) pass all visibility filters or
+get culled. Three emission paths:
+
+- [indoor-cull] reason=visibleCellIds-miss — when the ParentCellId
+ filter rejects the entity.
+- [indoor-cull] reason=frustum — when AABB frustum cull rejects.
+- [indoor-walk] — when the entity passes all filters and reaches the
+ draw list.
+
+Rate-limited to once per cellId per ~1 sec (30 frames at 30 Hz) via
+_lastIndoorProbeFrame dictionary. Bumped from Draw()'s top.
+
+Disambiguates hypothesis H3 (cull bug — cell entity dropped before
+draw).
+
+Co-Authored-By: Claude Opus 4.7 (1M context)
+EOF
+)"
+```
+
+---
+
+## Task 7: Instrument `WbDrawDispatcher` lookup + xform probes
+
+**Files:**
+- Modify: `src/AcDream.App/Rendering/Wb/WbDrawDispatcher.cs`
+
+These probes fire deeper in the per-MeshRef draw loop, where the render-data lookup happens and the `IsSetup` branch composes per-part transforms. The dispatcher's per-MeshRef body is around line 590-627.
+
+- [ ] **Step 1: Find the per-MeshRef body and the IsSetup branch**
+
+Open the file. Find the line `var renderData = _meshAdapter.TryGetRenderData(gfxObjId);` (or similar TryGetRenderData lookup inside the per-MeshRef draw loop). The relevant block is the if/else at line 607 (the `IsSetup` branch).
+
+- [ ] **Step 2: Add the `[indoor-lookup]` probe at the lookup site**
+
+Find the line that fetches the renderData (likely `var renderData = _meshAdapter.TryGetRenderData(gfxObjId);` or equivalent). Immediately AFTER that lookup and BEFORE the existing null/miss handling at line 595 (`if (diag) _meshesMissing++; continue;`), insert:
+
+```csharp
+ // [indoor-lookup] probe — emit once per cell entity per sec.
+ ulong _lookupCellId = (ulong)gfxObjId;
+ if (RenderingDiagnostics.IsEnvCellId(_lookupCellId)
+ && RenderingDiagnostics.ProbeIndoorLookupEnabled
+ && ShouldEmitIndoorProbe(_lookupCellId))
+ {
+ bool hit = renderData is not null;
+ bool isSetup = hit && renderData!.IsSetup;
+ int partCount = isSetup ? renderData!.SetupParts.Count : 0;
+
+ int partsHit = 0, partsMiss = 0;
+ if (isSetup)
+ {
+ foreach (var (partId, _) in renderData!.SetupParts)
+ {
+ if (_meshAdapter.TryGetRenderData(partId) is not null) partsHit++;
+ else partsMiss++;
+ }
+ }
+
+ bool hasEnvCellGeom = isSetup
+ && renderData!.SetupParts.Exists(t => (t.GfxObjId & 0x1_0000_0000UL) != 0);
+
+ Console.WriteLine(
+ $"[indoor-lookup] cellId=0x{_lookupCellId:X8} " +
+ $"hit={hit} isSetup={isSetup} partCount={partCount} " +
+ $"hasEnvCellGeom={hasEnvCellGeom} partsHit={partsHit} partsMiss={partsMiss}");
+ }
+```
+
+Note: this probe emits BEFORE the null-renderData early-`continue`, so a null lookup still emits `hit=false`. That's intentional — it tells us if the lookup itself failed (hypothesis H1 fallout).
+
+- [ ] **Step 3: Add the `[indoor-xform]` probe inside the IsSetup branch**
+
+Find the `if (renderData.IsSetup && renderData.SetupParts.Count > 0)` block (line 607 in current code). Inside the `foreach (var (partGfxObjId, partTransform) in renderData.SetupParts)` loop, AFTER the `var model = ComposePartWorldMatrix(...)` line, insert:
+
+```csharp
+ // [indoor-xform] probe — only for the cell's synthetic
+ // geometry part (bit 32 set, per WB's PrepareEnvCellMeshData
+ // line 1247). One line per cell per sec.
+ if ((partGfxObjId & 0x1_0000_0000UL) != 0
+ && RenderingDiagnostics.ProbeIndoorXformEnabled
+ && ShouldEmitIndoorProbe(partGfxObjId))
+ {
+ Console.WriteLine(
+ $"[indoor-xform] cellGeomId=0x{partGfxObjId:X16} " +
+ $"entityWorldT=({entityWorld.Translation.X:F2},{entityWorld.Translation.Y:F2},{entityWorld.Translation.Z:F2}) " +
+ $"meshRefT=({meshRef.PartTransform.Translation.X:F2},{meshRef.PartTransform.Translation.Y:F2},{meshRef.PartTransform.Translation.Z:F2}) " +
+ $"partT=({partTransform.Translation.X:F2},{partTransform.Translation.Y:F2},{partTransform.Translation.Z:F2}) " +
+ $"composedT=({model.Translation.X:F2},{model.Translation.Y:F2},{model.Translation.Z:F2})");
+ }
+```
+
+- [ ] **Step 4: Build**
+
+Run: `dotnet build src/AcDream.App/AcDream.App.csproj -c Debug`
+Expected: 0 errors.
+
+- [ ] **Step 5: Test (existing tests, sanity)**
+
+Run: `dotnet test tests/AcDream.Core.Tests/AcDream.Core.Tests.csproj -c Debug --filter "FullyQualifiedName~Rendering" --no-build --nologo`
+Expected: All Rendering tests (including new RenderingDiagnosticsTests) pass.
+
+- [ ] **Step 6: Commit**
+
+```bash
+git add src/AcDream.App/Rendering/Wb/WbDrawDispatcher.cs
+git commit -m "$(cat <<'EOF'
+feat(dispatcher): [indoor-lookup] + [indoor-xform] probes
+
+Instruments the per-MeshRef draw loop in WbDrawDispatcher:
+
+- [indoor-lookup]: per cell entity, dumps render-data hit/miss,
+ IsSetup, parts count, and a partsHit/partsMiss tally over the
+ SetupParts. Disambiguates hypothesis H2 (WB produces empty
+ ObjectRenderData with zero parts) and H6 (dispatcher fails to
+ traverse Setup).
+
+- [indoor-xform]: only fires for the cell's synthetic geometry part
+ (the SetupPart whose GfxObjId has bit 32 set, per WB's
+ PrepareEnvCellMeshData cellGeomId convention). Logs the three
+ composed transform translations: entityWorld, meshRef.PartTransform,
+ partTransform, and the final composed matrix translation. Disambiguates
+ hypothesis H5 (transform double-apply — composedT lands at 2 ×
+ cellOrigin).
+
+Rate-limited via existing _lastIndoorProbeFrame map.
+
+Co-Authored-By: Claude Opus 4.7 (1M context)
+EOF
+)"
+```
+
+---
+
+## Task 8: Build + visual capture procedure
+
+**Files:** none modified. Build verification + runtime data capture.
+
+- [ ] **Step 1: Full solution build**
+
+Run: `dotnet build AcDream.slnx -c Debug --nologo 2>&1 | tail -10`
+Expected: 0 errors, 0 warnings. All projects compile.
+
+- [ ] **Step 2: Run full test suite**
+
+Run: `dotnet test AcDream.slnx -c Debug --nologo --no-build 2>&1 | tail -15`
+Expected: New RenderingDiagnostics tests pass. Pre-existing failures in `DispatcherToMovementIntegrationTests`, `BSPStepUpTests`, and `MotionInterpreterTests` (8 total) remain — those are unrelated to this work. No NEW failures.
+
+- [ ] **Step 3: Gracefully close any prior AcDream.App instance**
+
+```powershell
+$proc = Get-Process -Name AcDream.App -ErrorAction SilentlyContinue
+if ($proc) {
+ $proc | ForEach-Object { $_.CloseMainWindow() | Out-Null }
+ $proc | ForEach-Object { if (-not $_.WaitForExit(5000)) { Stop-Process -Id $_.Id -Force } }
+ Start-Sleep -Seconds 3
+}
+```
+
+- [ ] **Step 4: Launch with all indoor probes enabled**
+
+```powershell
+$env:ACDREAM_DAT_DIR = "$env:USERPROFILE\Documents\Asheron's Call"
+$env:ACDREAM_LIVE = "1"
+$env:ACDREAM_TEST_HOST = "127.0.0.1"
+$env:ACDREAM_TEST_PORT = "9000"
+$env:ACDREAM_TEST_USER = "testaccount"
+$env:ACDREAM_TEST_PASS = "testpassword"
+$env:ACDREAM_DEVTOOLS = "1"
+$env:ACDREAM_PROBE_INDOOR_ALL = "1"
+$logPath = "launch.log"
+Remove-Item $logPath -ErrorAction SilentlyContinue
+dotnet run --project src\AcDream.App\AcDream.App.csproj --no-build -c Debug 2>&1 | Tee-Object -FilePath $logPath
+```
+
+Run this in the background (the launching tool supports `run_in_background: true`).
+
+- [ ] **Step 5: User reproduces the bug**
+
+In the running client:
+- Wait until in-world at Holtburg (8-12 s after launch).
+- Walk to Holtburg Inn (north of spawn — Fispur's Foodstuffs is visible).
+- Stand at the doorway. Then step inside. Look at the floor.
+- Walk around the inn interior.
+- Close the client window (graceful close — close button, NOT taskkill).
+
+- [ ] **Step 6: Grep the log for probe output**
+
+```bash
+grep -E "\[indoor-" launch.log | head -100
+```
+
+Expected: a mix of `[indoor-upload] requested`, `[indoor-upload] completed`, `[indoor-walk]`, `[indoor-lookup]`, `[indoor-xform]`, `[indoor-cull]` lines for the Holtburg Inn cell IDs (0xA9B40100-ish range).
+
+- [ ] **Step 7: Identify which hypothesis matches**
+
+Compare the captured log against the hypothesis table in the spec (§3 of `2026-05-19-indoor-cell-rendering-fix-design.md`):
+
+| Hypothesis | Probe pattern in log |
+|---|---|
+| H1 — WB silently returns null | `[indoor-upload] requested` lines exist but NO matching `completed` lines for cell ids |
+| H2 — Empty batches | `[indoor-upload] completed ... cellGeomVerts=0` |
+| H3 — Cull bug | `[indoor-cull]` lines for cell entity ids with `reason=visibleCellIds-miss` |
+| H4 — Double-spawn | `[indoor-lookup] partCount=N` where N includes static object IDs that ALSO appear in the entity walk — cross-check against `[indoor-walk]` lines |
+| H5 — Transform double-apply | `[indoor-xform] composedT` translation roughly 2× the cell's known world origin |
+| H6 — MeshRefs structure | `[indoor-lookup] hit=true isSetup=true partCount>0 partsHit=0` (all parts missing) |
+
+- [ ] **Step 8: Document the captured data + matched hypothesis**
+
+Create a short investigation note at `docs/research/2026-05-19-indoor-cell-rendering-probe-capture.md` summarizing:
+- The exact `[indoor-*]` log lines captured (or a representative subset).
+- The matched hypothesis number.
+- A one-line proposed fix sketch.
+
+This file will be referenced by Phase 2's spec.
+
+- [ ] **Step 9: Commit the capture note**
+
+```bash
+git add docs/research/2026-05-19-indoor-cell-rendering-probe-capture.md
+git commit -m "$(cat <<'EOF'
+docs(research): Phase 1 indoor probe capture — identifies hypothesis HX
+
+[Replace HX with the matched hypothesis number, and summarize the
+captured log evidence in 1-2 sentences.]
+
+Co-Authored-By: Claude Opus 4.7 (1M context)
+EOF
+)"
+```
+
+- [ ] **Step 10: Hand off to Phase 2 design**
+
+The captured data is now the input to Phase 2's design. Either:
+- Amend `docs/superpowers/specs/2026-05-19-indoor-cell-rendering-fix-design.md` with a Phase 2 section, OR
+- Write a new spec `docs/superpowers/specs/YYYY-MM-DD-indoor-cell-rendering-phase2-fix-design.md` targeting the identified hypothesis.
+
+The plan for Phase 2 follows the standard brainstorming → writing-plans → executing-plans flow.
+
+---
+
+## Acceptance Criteria
+
+- [x] All eight tasks complete + committed.
+- [ ] `dotnet build` clean. `dotnet test` clean (no new failures; pre-existing 8 physics/input failures unchanged).
+- [ ] Probe captured at Holtburg Inn produces enough log evidence to identify which of H1-H6 is the root cause.
+- [ ] Capture note written and committed.
+- [ ] Phase 2 design follow-up spec started.