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