docs: #106 pinned — outdoor membership freezes at landblock boundaries

The 53MB flap-probe capture (user live-reproduced the broken-house entry)
plus 3-agent analysis settles the day: playerCell froze at 0xA9B40031 for
10,449 frames spanning ~130m of outdoor walking into landblock A9B3 and a
stand INSIDE an A9B3 cottage. Within-landblock outdoor flips are 96/96
clean; all 10 successful indoor entries were same-landblock buildings; the
single cross-landblock entry failed. The render flood independently drew the
A9B3 interior cells the whole time — rendering is downstream and healthy;
membership is the broken layer (feedback_render_downstream_of_membership,
proven again). The stale render anchor also explains the outdoor running
distortion; the capture refutes flood-level causes outdoors (26,960/26,960
outdoor frames rigid at outPolys=1 vis=1).

Files #106 (HIGH, physics/membership) with fix pointers: ResolveCellId /
AddAllOutsideCells cross-landblock proposal, the b3ce505 outdoor-sweep gate
(possible stopgap fallout, like #99), retail find_cell_list :308742 +
LandDefs.get_outside_lcoord. Reframes #105: largely superseded by #106;
residual (single wall missing while membership indoor-correct) stays open
with all tripwires armed. Handoff:
docs/research/2026-06-09-105-capture-analysis-membership-landblock-pin.md

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs/research/2026-06-09-105-capture-analysis-membership-landblock-pin.md

@@ -0,0 +1,90 @@
+# #105 capture analysis — outdoor membership FREEZES at landblock boundaries (#106 PINNED)
+
+**Date:** 2026-06-09 (evening). **Branch:** `claude/thirsty-goldberg-51bb9b`.
+**Evidence:** `flap-105-capture.log` (53 MB UTF-16LE, `ACDREAM_PROBE_FLAP=1`, 136,736 lines,
+30,698 `[flap-cam]` frames, 16,587 `[render-sig]`, 750 `[pv-trace]`), analyzed by 3 parallel
+workers (throwaway scripts `q105_*.py` in the worktree root). User live-reproduced during
+capture: entered a cottage and "EVERYTHING disappears, like I'm standing outside."
+
+---
+
+## 0. TL;DR
+
+1. **#106 PINNED: the player's OUTDOOR cell membership never crosses a landblock boundary.**
+   `playerCell` froze at `0xA9B40031` (line 93363) and stayed frozen for **10,449 frames**:
+   ~130 m of outdoor walking south across the `A9B4→A9B3` boundary (player y reaching −109.65
+   in A9B4-local coords = ~82 m inside A9B3) plus an 8,929-frame stand INSIDE an A9B3 cottage.
+   Zero indoor candidates ever flickered. Within-landblock outdoor transitions are clean
+   (96/96, e.g. `0x0031↔0x0029` flipping exactly at the x=144 cell line).
+2. **The discriminator landed hard:** all **10 successful** outdoor→indoor entries this
+   session (7 distinct buildings: 0170, 0150, 0164, 016E, 016C, 010B, 0118) were buildings in
+   the SAME landblock as the player's outdoor cell — each a single clean flip with the viewer
+   cell trailing ~48 frames (camera boom still outside), no flicker. The ONE failing entry was
+   the only CROSS-landblock building entered.
+3. **Rendering is downstream and healthy:** while membership said "outdoor," `[render-sig]`
+   shows the flood drawing the A9B3 interior cells (`0xA9B30100/0103/.../0110`) — the renderer
+   could see the rooms membership refused to enter. 89 distinct indoor cells flood under
+   outdoor roots across the session; ids==draw (no misses); **no never-flooding building
+   exists**; **no indoor flood ever collapsed empty** (all 17 indoor roots always vis≥2).
+   `feedback_render_downstream_of_membership` proven again.
+4. **The outdoor "running distortion" is the same freeze:** the render root stays anchored at
+   the stale outdoor cell while the player runs away from it (10,415-frame root run at
+   `0x0031`), so the whole view is built from a wrong anchor. The capture REFUTES flood-level
+   causes outdoors: in all 26,960 outdoor-root frames, `outPolys=1` and `vis=1` with zero
+   exceptions.
+5. **The §4 indoor flap is unchanged and separate:** vis oscillation exists only under indoor
+   roots (520 changes, longest 9 consecutive flips, cells 0x013F/0x0143/0x0150/0x0171) plus
+   ~11 one-to-three-frame OUT↔IN root blips at doorways (e.g. lines 31704..31713) — the known
+   doorway flap, untouched today.
+
+## 1. What #106 explains vs what stays in #105
+
+- **#106 explains:** "enter house → everything disappears, looks like outside" (cross-landblock
+  buildings), most of the day's per-session "some houses broken" reports (which houses break
+  depends on where you've walked = which boundaries you crossed), and the outdoor running
+  distortion (stale render anchor).
+- **Still #105 (residual, twice-observed earlier):** a single wall section missing
+  (sky/clear color) while membership/viewer were demonstrably INDOOR-correct
+  (`viewerCell=0171`, props drawn, collision present). All data/upload/registration layers are
+  exonerated by 4 silent tripwire rounds; if it reproduces, the draw-level clip path (§4
+  family) is the remaining suspect space.
+
+## 2. Fix pointers for #106 (next session)
+
+- **Membership chokepoint:** the outdoor candidate-cell proposal. The capture shows the
+  resolver flips outdoor cells fine WITHIN a landblock but never proposes another landblock's
+  outdoor cell. Look at `PhysicsEngine.ResolveCellId` + `CellTransit.AddAllOutsideCells`
+  (its coord-convention bug was fixed 2026-05-25 — `feedback_latent_bug_masked_by_fallback`;
+  cross-landblock proposals may be missing or clamped to the current landblock's 8×8 grid).
+- **Check the `b3ce505` #98 stopgap first:** it GATED the outdoor sweep (a flagged WORKAROUND
+  that already caused #99). If the gate suppresses the sweep that would propose
+  neighboring-landblock cells, #106 is its fallout — fixing the root (per-cell shadow
+  architecture A6.P4) or narrowing the gate may be the real fix. Read
+  `claude-memory/project_physics_collision_digest.md` DO-NOT-RETRY before touching anything.
+- **Retail oracle:** `CObjCell::find_cell_list` Position-variant
+  (`acclient_2013_pseudo_c.txt:308742-308783`) + `LandDefs` outside-coordinate handling
+  (`get_outside_lcoord` family) — retail resolves outdoor cells from GLOBAL coordinates, so
+  landblock crossings are inherent. Cross-check ACE `Physics/Common/LandDefs.cs`.
+- **Cheap probe for the fix loop:** `ACDREAM_PROBE_CELL=1` (`[cell-transit]`, low volume)
+  while walking across each Holtburg boundary; acceptance in #106's entry.
+
+## 3. Apparatus notes (carried forward)
+
+- `[pv-trace]` is hard-gated to roots `0x016F..0x0175` (`PortalVisibilityBuilder.cs:606-647`)
+  and `BuildFromExterior` has **NO trace hook** — outside-looking-in cull reasons are
+  unobservable until one is added (needed if #105's residual reproduces).
+- `[flap]`'s `vis`/`outPolys` are PRE-merge (emitted in `Build`, before
+  `MergeNearbyBuildingFloods` in `RetailPViewRenderer.cs:48-61`); post-merge truth is
+  `[render-sig] ids=/draw=`.
+- Tripwires still live (keep until #105/#106 close): rounds 1–3 + `[up-null]` (known-benign
+  ids `0x010002B4`, `0x010008A8` — deterministic empty meshes, ignore).
+- Capture + scripts: `flap-105-capture.log`, `q105_*.py` (untracked throwaways).
+
+## 4. The day's full arc (for the next session's orientation)
+
+dat-reader direction chosen → read path EXONERATED (audit + 1.1M-read hammer, `b3920d8`) →
+teardown dispose-during-read AV FIXED (`8fadf77`) → white-walls trapped through 4 tripwire
+rounds (all silent) → live capture → **#106 pinned (membership, cross-landblock)**. The day's
+"render bug" was a physics bug all along, exactly per
+`feedback_render_downstream_of_membership`. Next session: fix #106 (membership/A6 territory,
+read the physics digest first).