docs(A): wrap Render Residual A — handoff + roadmap for the core inside render

Residual A (camera collision = verbatim SmartBox::update_viewer) is SHIPPED +
user-kept (0ffc3f5/5177b54/9e70031). Wrap it and hand off to the render session:

- New canonical handoff (docs/research/2026-06-05-render-residual-a-shipped-core-
  inside-render-handoff.md): what A shipped, what A EXPOSED (the render roots at the
  viewer cell — clipRoot=CameraCell, GameWindow.cs:7322 — and A made that cell
  accurate, so the PVS flood from the viewer cell doesn't reach the player's cell →
  cellar floor drops), the reframing (the user's "step C" = the CORE inside render /
  R1 completion, NOT R2 outside-looking-in), the evidence-first job, KEEP/DON'T, the
  kickoff prompt.
- CLAUDE.md banner: A SHIPPED; next = core inside render (R1 completion).
- Render redesign spec: 2026-06-05 sync note (A shipped; R1 is actually incomplete —
  the bleed + cellar-floor drop are the unfinished flood/seal; next is R1, not R2).

The visible problems (bleed + the floor A exposed) are the same family: the inside
path still draws the whole outdoor world instead of retail's "inside → DrawInside
only". A faithful DrawInside seals them by construction (render spec 2026-06-02 §2).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

CLAUDE.md

@@ -763,23 +763,24 @@ H1 (PVS grounding) or H2 (`PortalSide` side-test) — both evidence-disproven.
 **Currently working toward: M1.5 — Indoor world feels right** (resumed
 from 2026-05-20 baseline after Phase O ship).
 
-**2026-06-05 — P2 cellar-lip wedge FIXED; next = Render Residual A (camera collision) (READ THIS FIRST).**
+**2026-06-05 — Render Residual A (camera collision) SHIPPED + user-kept; next = the CORE INSIDE RENDER (R1 completion) (READ THIS FIRST).**
-The "stuck on the last cellar step" wedge is FIXED + visual-verified (user: "Yes all works!" — cellar
+Residual A = a verbatim port of retail `SmartBox::update_viewer` (pc:92761): the indoor sweep's start
-ascent smooth, inn door still BLOCKS, generic step-up climbs). Root cause: `Transition.CheckOtherCells`
+cell is seated at the head-PIVOT via `AdjustPosition` (pc:280009) → `find_visible_child_cell` (pc:311397),
-collided the other cells against a STALE pre-step-up `footCenter`; retail's `check_other_cells` reads the
+plus the two fallbacks + cellId==0 snap-to-player. Commits `0ffc3f5` (spec) / `5177b54` (Core primitives)
-LIVE `sphere_path.global_sphere` (pc:272735). Fix = re-read `footCenter = sp.GlobalSphere[0].Origin` in
+/ `9e70031` (`ResolveResult.Ok` + `SweepEye` orchestration); TDD, 11 new tests, no regression (Core
-`RunCheckOtherCellsAndAdvance` (commits `cc4590f`/`9fdf6a5`/`41db027`; 0/29→20/29 captured wedge frames
+1326p/4f/1s, App 179p). **Key finding (live capture):** A's V1 sweep ALREADY contained the eye
-climb; zero regression; Core 1317p/4f/1s). This DISPROVED the prior "find_walkable never called" framing
+(`eyeInRoot=Y` 99.75%, `viewerCell` never 0) — so A is a faithfulness completion, not the fix for the
-(it was a probe-reading artifact — `find_walkable` IS called; the `[fc-dispatch]` cell logged the carried
+dominant bluish void. **What A EXPOSED (the bridge to the next phase):** the render roots at the VIEWER
-cell, not the iterated one). The remaining 9/29 are a separate `(0,-1,0)` sliding-normal +Y-kill that did
+cell (`clipRoot = visibility.CameraCell`, GameWindow.cs:7322, Phase W V1 "one viewpoint"); A made that
-NOT manifest in live play (buggy-trajectory artifact; documented as `DocumentsResidualWedge_*`, deferred —
+cell ACCURATE (the eye's real cell), so when the player is in the cellar but the eye is up in the room,
-slide territory). **NEXT per the plan = Render Residual A: camera collision** — verbatim port of retail
+`clipRoot = room` and the PVS flood from the room does NOT reach the cellar → the cellar floor drops.
-`SmartBox::update_viewer` (pc:92761) to keep the 3rd-person chase eye INSIDE the player's cell (fixes
+The user chose **"Keep it"** (the faithful viewpoint) over revert. **NEXT = the CORE inside render (R1
-interior walls going grey/transparent while inside). User-confirmed approach (verbatim port, no hybrids)
+completion)** — make `DrawInside` flood + seal correctly from the viewer cell so the cottage/cellar
-+ order (A→C→B; C = outside-looking-in `DrawPortal`, B = particles). **CANONICAL PICKUP:**
+interior is SEALED: no bluish void, no see-through-to-other-buildings BLEED, cellar floor draws. This
-[`docs/research/2026-06-05-camera-collision-residual-a-handoff.md`](docs/research/2026-06-05-camera-collision-residual-a-handoff.md)
+(NOT the handoff-era "C / outside-looking-in", which is R2, a later phase) is what fixes the visible
-(+ cellar-lip writeup in the top banner of
+problems; the locked design already exists. **CANONICAL PICKUP:**
-[`docs/research/2026-06-04-p2-cellar-lip-flatfloor-cp-handoff.md`](docs/research/2026-06-04-p2-cellar-lip-flatfloor-cp-handoff.md)).
+[`docs/research/2026-06-05-render-residual-a-shipped-core-inside-render-handoff.md`](docs/research/2026-06-05-render-residual-a-shipped-core-inside-render-handoff.md)
+(+ the LOCKED render design [`docs/superpowers/specs/2026-06-02-render-pipeline-redesign-design.md`](docs/superpowers/specs/2026-06-02-render-pipeline-redesign-design.md)).
 
 **2026-06-03 — P1 membership DONE + P2 active (history; cellar-lip now FIXED per the 2026-06-05 banner above).** The verbatim spatial-pipeline
 port (master plan

docs/research/2026-06-05-render-residual-a-shipped-core-inside-render-handoff.md

@@ -0,0 +1,216 @@
+# Handoff — Render Residual A SHIPPED; next = the CORE inside render (R1 completion) — 2026-06-05
+
+> **Canonical pickup for the next (render) session. Read this FIRST.** Residual A (camera collision)
+> is a faithful verbatim port of `SmartBox::update_viewer` — shipped, tested, user-kept. It made the
+> render's viewpoint *accurate*, which **exposed** the real next problem with precision: the inside
+> render does not flood/seal correctly from the (now-correct) viewer cell. The "step C" the user asked
+> for is therefore **not** the handoff-era "C / outside-looking-in" — it is the **core inside render
+> (R1 completion)**. Branch `claude/thirsty-goldberg-51bb9b`. PowerShell on Windows; launch logs are
+> UTF-16 (`Select-String` / `rg --encoding utf-16-le`, NOT GNU grep).
+
+---
+
+## 0. TL;DR
+
+- **SHIPPED (A):** verbatim `SmartBox::update_viewer` — indoor start-cell seated at the head-pivot
+  (`AdjustPosition` → `find_visible_child_cell`) + the two fallbacks + cellId==0 snap-to-player.
+  Commits `0ffc3f5` (spec) / `5177b54` (Core primitives) / `9e70031` (SweepEye orchestration). TDD,
+  11 new tests, no regression. User-kept (chose "Keep it" over revert).
+- **The live-capture finding that scoped A:** A's V1 sweep *already* contained the eye (`eyeInRoot=Y`
+  99.75%, `viewerCell` never 0, indoor collide 97.6%). So A is a faithfulness completion, not a
+  visible-bug fix. The dominant inside-cottage **bluish void / see-through-to-other-buildings is NOT
+  the camera — it is the render seal.**
+- **What A EXPOSED (the handoff's whole point):** the render roots at the **viewer cell**
+  (`clipRoot = visibility.CameraCell`, GameWindow.cs:7322; Phase W V1 "one viewpoint"). A made that
+  cell *accurate* (the eye's real, collided cell). So when you stand in the cellar but the eye is up
+  in the room, `clipRoot = the room`, and the PVS flood from the room **does not reach the cellar** →
+  **the cellar floor drops.** Before A, `viewerCell ≈ playerCell` (the sweep started from the feet
+  cell), which *accidentally masked* this. The user accepted this interim floor-drop to keep the
+  faithful viewpoint.
+- **NEXT = the core inside render (R1 completion):** make `DrawInside` flood + seal correctly from the
+  viewer cell. This fixes BOTH the **bleed** (point 1) AND the **floor** A exposed — they are the same
+  family. The locked design already exists:
+  [`docs/superpowers/specs/2026-06-02-render-pipeline-redesign-design.md`](../superpowers/specs/2026-06-02-render-pipeline-redesign-design.md).
+- **Test baseline:** Core **1326 pass / 4 fail (documented) / 1 skip**; App **179 pass / 0 fail**.
+  The 4 Core fails are pre-existing (2× `DoorBugTrajectoryReplay` LiveCompare, `BSPStepUpTests.D4`,
+  `DoorCollisionApparatus`).
+
+---
+
+## 1. What shipped — Residual A (verbatim `SmartBox::update_viewer`, pc:92761)
+
+| Commit | What | Layer |
+|---|---|---|
+| `0ffc3f5` | design spec (`docs/superpowers/specs/2026-06-05-residual-a-camera-collision-design.md`) | docs |
+| `5177b54` | `CellTransit.FindVisibleChildCell` (CEnvCell::find_visible_child_cell pc:311397) + `PhysicsEngine.AdjustPosition` (CPhysicsObj::AdjustPosition pc:280009) | Core |
+| `9e70031` | `ResolveResult.Ok` (surfaces `find_valid_position != 0`) + `PhysicsCameraCollisionProbe.SweepEye` orchestration (start-cell seating + fallback 1 + fallback 2 + cellId==0 snap-to-player) | Core + App |
+
+The orchestration mirrors `update_viewer` end-to-end: indoor (`objcell_id >= 0x100`) seats the sweep's
+start cell at the **head-pivot** via `AdjustPosition` (the cellar lip: feet in the low connector, head
+up at floor level); sweep `pivot → sought-eye` from that start; on success `set_viewer(curr_pos)`,
+`viewer_cell = curr_cell`; fallback 1 = `AdjustPosition(sought_eye)`; fallback 2 / no-cell = snap to
+player, `viewer_cell = null`. `SweepEye` gained a `playerPos` arg (for the snap).
+
+**Why A's visible payoff was nil this session (don't be surprised):** the seating only differs from the
+feet cell when the feet are in a *thin connector* cell while the head is in a taller neighbour (the lip
+— a transient). Two live captures: in the cottage room every frame had `start == cell` (0 seated of
+80,605); in the cellar the seating *did* fire (1,687 frames, `start != cell`). No fallback ever fired
+(`ok=False`: 0). So A is faithful + correct; its job was to make the viewpoint accurate, which it did.
+
+## 2. The exposure (READ THIS — it is the bridge to the next phase)
+
+The render roots + projects from **one viewpoint = the viewer cell** (Phase W V1, GameWindow.cs:7322,
+7330-7333: *"the render root (clipRoot = the viewer cell). ONE viewpoint"*). `PortalVisibilityBuilder.Build(clipRoot, viewerEye, …)`
+floods the PVS from `clipRoot`.
+
+A changed `viewerCell` from `≈ playerCell` (V1, sweep from the feet cell) to **the eye's actual cell**
+(seated at the pivot). Live proof, player in the cellar (`playerCell=0xA9B40174`):
+
+```
+[flap-cam] root=0xA9B40171 viewerCell=0xA9B40171 playerCell=0xA9B40174  eye=(155,12,96.5) player=(153,9,93)   ×1466 frames
+```
+
+`clipRoot = viewerCell = 0171` (the room, where the eye is) while the player is in `0174` (the cellar).
+The PVS flood from the room **does not reach the cellar** → the cellar floor (the player's cell) is not
+drawn → **missing floor**. This is exactly the spec's predicted symptom: §1.3 + §8 call the grey/missing
+cellar floor a **sealing bug** (the closed cell mesh not covering pixels, OR the flood not reaching the
+cell). **Cause unconfirmed — confirm it first (evidence-first, §4 below).**
+
+The **bleed** (point 1: walls bluish, other buildings/particles/NPCs visible through them from inside)
+is the same family: the inside path still draws the **whole outdoor world** then layers cell shells on
+top, instead of retail's "inside → `DrawInside` only" (spec §2). A faithful `DrawInside` makes the bleed
+impossible *by construction*.
+
+## 3. The reframing — "C" is the CORE inside render, not outside-looking-in
+
+The handoff-era residual letters (A camera / B particles / **C outside-looking-in**) map onto the locked
+render spec's phases as: A camera (DONE), B → **R1b** (#104 particles), **C → R2** (`DrawPortal`,
+street→interior). **R2 is a LATER phase.** The visible problems the user is hitting — the bleed AND the
+floor A exposed — are **R1 (the core per-cell `DrawInside` flood+seal)**, which shipped only *partially*
+(2026-06-03: the flap fix + basic shells + inside-looking-out, but NOT the "inside → DrawInside only"
+inversion, NOT the general-case flood from `viewerCell != playerCell`). **The next session finishes R1.**
+
+## 4. The job (next session) — evidence-first, then verbatim PView
+
+1. **Read the locked design + its 4 research docs (in the spec's "Read first" list):**
+   `docs/superpowers/specs/2026-06-02-render-pipeline-redesign-design.md` →
+   `docs/research/2026-06-02-render-pipeline-redesign-handoff.md` (root cause, the three-gate failure) →
+   `…-retail-render-pipeline-full-reference.md` (the PView + `DrawCells` seal) →
+   `…-acdream-render-pipeline-inventory-and-failures.md` (the `WbDrawDispatcher.cs:1756` bypass, the
+   parallel BFS, the terrain Skip model) → `…-render-reference-crosscheck.md` (why WB two-pipe is wrong).
+2. **Confirm the floor cause FIRST (do NOT guess — spec §8):** launch with `ACDREAM_PROBE_FLAP=1`
+   `ACDREAM_PROBE_VIS=1` `ACDREAM_PROBE_SHELL=1`; stand in the cellar, get the eye up in the room
+   (`viewerCell=room`, `playerCell=cellar`). Read `[vis]` (does `OrderedVisibleCells` include the cellar
+   when rooted at the room?) + `[shell]` (does the cellar shell draw?) + dump the cellar EnvCell mesh
+   (is the floor polygon present + front-facing?). This decides: **PVS-flood-not-reaching** vs
+   **cell-mesh-not-sealing**. Get a screenshot EARLY (memory `render-one-gate`).
+3. **Port the PView seal/flood verbatim (spec §2 + §4):** the binary top-level decision (inside →
+   `DrawInside` only — removes the global outdoor pass → kills the bleed by construction) + the per-cell
+   `DrawInside` loop (landscape-through-door → conditional Z-only clear → per-cell shells → per-cell
+   objects → per-cell particles). Retail anchors: `RenderNormalMode` 0x453aa0, `PView::DrawInside`
+   0x5a5860, `ConstructView` 0x5a57b0, `DrawCells` 0x5a4840 (spec §11 has the full index).
+4. **VALIDATE — visual gate (spec R1 gate):** Holtburg cottage + cellar — sealed interior (opaque walls,
+   **solid floor**, ceiling), sky/terrain through the door only, **no bluish void, no bleed** (no other
+   buildings/particles/NPCs through walls), no terrain under the floor. Build + Core(1326p/4f/1s)/App(179p) green.
+
+## 5. KEEP / DON'T-REDO
+
+**KEEP (do not reopen):**
+- **Residual A** (the 3 commits). The viewer cell is now accurate — that is the *input* the render needs.
+  Do NOT revert it to mask the floor (the user explicitly chose to keep the faithful viewpoint).
+- The Phase W V1 "one viewpoint" (clipRoot = viewer cell, project from the eye) — GameWindow.cs:7322-7338.
+- The Stage-1 membership port + the blue-hole fix (`UpdatePlayerCurrCell`, player-only render-root).
+- `PortalVisibilityBuilder` / `ClipFrame` / `EnvCellRenderer` / `TerrainModernRenderer` / the WB mesh
+  pipeline (spec §3 KEEP).
+
+**DON'T:**
+- Don't re-add a `CurrCell` write inside `ResolveWithTransition` / `ResolveCellId` (the blue-hole clobber).
+- Don't reintroduce the WB two-pipe stencil / `isInside` gate / AABB grace-frame for the root (spec §8).
+- Don't relax the faithful terrain `Skip` to "fix" the grey floor (spec §1.3 — it's a sealing bug, not a
+  terrain-clip bug).
+- Don't jump to R2 (outside-looking-in / `DrawPortal`) — R1 (the inside seal+flood) is first.
+
+## 6. KEY FILES + ANCHORS
+
+```
+RENDER (the next phase)
+  src/AcDream.App/Rendering/GameWindow.cs (OnRender ~7300-7610)   ← clipRoot=viewerCell (7322); binary decision lives here
+  src/AcDream.App/Rendering/PortalVisibilityBuilder.cs            ← the PVS BFS (KEEP; the flood to harden/port)
+  src/AcDream.App/Rendering/InteriorRenderer.cs                   ← per-cell DrawInside loop (partial)
+  src/AcDream.App/Rendering/EnvCellRenderer.cs                    ← per-cell shell mesh (Render(pass,{cellId}))
+  src/AcDream.App/Rendering/WbDrawDispatcher.cs (~1756)           ← the ParentCellId==null bypass to delete
+  src/AcDream.App/Rendering/ClipFrameAssembler.cs / CellVisibility.cs
+  docs/superpowers/specs/2026-06-02-render-pipeline-redesign-design.md  ← LOCKED design (§2 model, §4 seal, §7 phases, §11 anchors)
+
+CAMERA (A — shipped, the input)
+  src/AcDream.App/Rendering/PhysicsCameraCollisionProbe.cs        ← SweepEye = verbatim update_viewer
+  src/AcDream.Core/Physics/CellTransit.cs  FindVisibleChildCell   ← pc:311397
+  src/AcDream.Core/Physics/PhysicsEngine.cs AdjustPosition        ← pc:280009
+
+PROBES
+  ACDREAM_PROBE_FLAP=1   [flap-cam] root/viewerCell/playerCell/eyeInRoot  +  [flap] PVS BFS  +  [flap-sweep] camera (start vs cell, ok)
+  ACDREAM_PROBE_VIS=1    [vis] OrderedVisibleCells + OutsideView
+  ACDREAM_PROBE_SHELL=1  [shell] per-cell shell draw
+  ACDREAM_PROBE_CELL=1   [cell-transit] player CellId changes
+```
+
+## 7. RUNNING THE CLIENT (PowerShell; `+Acdream` spawns in the Holtburg cottage)
+
+```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_PROBE_FLAP="1"; $env:ACDREAM_PROBE_VIS="1"; $env:ACDREAM_PROBE_SHELL="1"
+dotnet run --project src\AcDream.App\AcDream.App.csproj --no-build -c Debug *>&1 | Tee-Object -FilePath launch.log
+```
+Build green BEFORE launching. Logs are UTF-16. Close gracefully (✕ / Alt+F4) so ACE clears the session in ~3-5s.
+
+## 8. KICKOFF PROMPT (copy-paste for the next session)
+
+```
+Continue acdream M1.5 render work: the CORE INSIDE RENDER (R1 completion) — make DrawInside flood + seal
+correctly from the viewer cell so the cottage/cellar interior is SEALED: no bluish void, no see-through-to-
+other-buildings BLEED, and the CELLAR FLOOR draws. This is what the user means by "step C" — it is NOT the
+handoff-era "C / outside-looking-in" (that is R2, a later phase). Branch claude/thirsty-goldberg-51bb9b
+(do NOT branch/worktree; do NOT push without asking; NEVER git stash/gc). PowerShell on Windows; launch
+logs are UTF-16 (Select-String / rg --encoding utf-16-le, NOT GNU grep). Use superpowers:systematic-
+debugging; the render redesign DESIGN is already LOCKED (read the spec), so this is execution + an
+evidence-first floor-cause confirmation, not a re-brainstorm.
+
+READ FIRST (in order):
+1. docs/research/2026-06-05-render-residual-a-shipped-core-inside-render-handoff.md  (THIS handoff — what
+   A shipped, what A EXPOSED §2, the reframing §3, the job §4, KEEP/DON'T §5, files §6).
+2. docs/superpowers/specs/2026-06-02-render-pipeline-redesign-design.md  (the LOCKED design — §2 the one
+   model, §4 the seal mechanics, §7 phases/gates, §11 decomp anchors) + its 4 "Read first" research docs.
+3. memory: reference_render_pipeline_state.md, feedback_render_one_gate.md,
+   feedback_render_downstream_of_membership.md, feedback_verify_render_seal_before_layering.md.
+
+STATE: Residual A (camera collision) SHIPPED + user-kept (commits 0ffc3f5/5177b54/9e70031) — verbatim
+SmartBox::update_viewer; the viewer cell is now ACCURATE. That accuracy EXPOSED the next problem: the
+render roots at the viewer cell (clipRoot=visibility.CameraCell, GameWindow.cs:7322), and the PVS flood
+from the viewer cell does NOT reach the player's cell when they differ (eye in the room, player in the
+cellar → clipRoot=room → cellar floor not drawn). Same family as the bleed (the inside path still draws
+the whole outdoor world instead of "inside → DrawInside only").
+
+THE JOB (evidence-first, then verbatim PView):
+1. Confirm the floor cause FIRST (spec §8 flags it unconfirmed): launch with ACDREAM_PROBE_FLAP/_VIS/_SHELL,
+   stand in the cellar with the eye up in the room (viewerCell=room, playerCell=cellar), read [vis]
+   (is the cellar in OrderedVisibleCells when rooted at the room?) + [shell] + dump the cellar EnvCell
+   mesh (floor poly present + front-facing?). Decide PVS-flood-not-reaching vs cell-mesh-not-sealing.
+   Screenshot EARLY.
+2. Port the PView seal/flood verbatim (spec §2 + §4): the binary top-level decision (inside → DrawInside
+   ONLY — removes the global outdoor pass → kills the bleed by construction) + the per-cell DrawInside loop
+   (landscape-through-door → conditional Z-only clear → per-cell shells → per-cell objects → per-cell
+   particles). Anchors: RenderNormalMode 0x453aa0, PView::DrawInside 0x5a5860, ConstructView 0x5a57b0,
+   DrawCells 0x5a4840.
+3. VALIDATE — visual gate: Holtburg cottage + cellar sealed (opaque walls, SOLID FLOOR, ceiling), sky/
+   terrain through the door only, NO bluish void, NO bleed. Build + Core(1326p/4f/1s)/App(179p) green.
+
+DON'T: revert A to mask the floor (user chose to keep the faithful viewpoint); re-add a CurrCell write in
+ResolveWithTransition/ResolveCellId (blue-hole); reintroduce the WB two-pipe / isInside gate / AABB grace
+(spec §8); relax the faithful terrain Skip (spec §1.3 — it's a sealing bug); jump to R2 (outside-looking-in)
+before R1 (the inside seal+flood) is done.
+
+TEST BASELINE: Core 1326 pass / 4 fail (documented: 2× DoorBugTrajectoryReplay LiveCompare, BSPStepUpTests.D4,
+DoorCollisionApparatus) / 1 skip. App 179 pass / 0 fail. Branch HEAD 9e70031 (+ this handoff commit).
+```

docs/superpowers/specs/2026-06-02-render-pipeline-redesign-design.md

@@ -245,6 +245,14 @@ the closest-first order (early-Z) are the mitigations. Measure at the R1 gate; d
 > A = camera-collision (walls grey while inside; eye outside the cell) → fold into R4 or a focused phase;
 > B = particles through the floor → **R1b** (#104); C = transparent walls from the street → **R2** below.
 > Canonical: [`docs/research/2026-06-03-membership-and-bluehole-shipped-handoff.md`](../../research/2026-06-03-membership-and-bluehole-shipped-handoff.md).
+>
+> **UPDATE 2026-06-05:** Residual **A (camera collision) SHIPPED** as a verbatim `update_viewer` port
+> (commits `0ffc3f5`/`5177b54`/`9e70031`). It made the viewer cell (which this pipeline roots on,
+> `clipRoot = CameraCell`) **accurate**, which exposed that **R1 is actually INCOMPLETE**: the
+> "inside → `DrawInside` only" inversion + the general-case flood were not finished, so the **bleed**
+> (other buildings through walls) + the **cellar-floor drop** (PVS flood from the viewer cell doesn't
+> reach the player's cell) remain. **The next phase is R1 completion (this §2/§4 work), NOT R2.**
+> Canonical: [`docs/research/2026-06-05-render-residual-a-shipped-core-inside-render-handoff.md`](../../research/2026-06-05-render-residual-a-shipped-core-inside-render-handoff.md).
 
 **Retail anchors:** `RenderNormalMode @ 0x453aa0` (binary decision), `PView::DrawInside @ 0x5a5860`,
 `ConstructView @ 0x5a57b0`, `DrawCells @ 0x5a4840` (the seal + the three per-cell loops), fact 8