diff --git a/docs/research/2026-06-03-p0-conformance-apparatus-notes.md b/docs/research/2026-06-03-p0-conformance-apparatus-notes.md
index 83a8972..9bd744f 100644
--- a/docs/research/2026-06-03-p0-conformance-apparatus-notes.md
+++ b/docs/research/2026-06-03-p0-conformance-apparatus-notes.md
@@ -64,7 +64,39 @@ retail loads, so a geometrically-correct containment answer is the retail answer
 | `find_cell_list` doorway-threshold pick | **retail cdb trace** | Task 6 — USER GATE / mine existing traces |
 | PVS visible-set | retail cdb `cell_draw_list` trace | deferred to P4 (Task 7 scaffold) |
 
-## P1-entry checklist (filled at end of P0)
+## Existing retail traces — mined, NOT usable for membership
 
-- [ ] Threshold golden GREEN (acdream already matches retail) or RED (P1 must fix) — recorded here.
-- [ ] "P0 gate met: ≥1 retail-trace-backed assertion exists" — stated explicitly so P1 can begin.
+`docs/research/2026-05-21-a6-captures/*/retail.log` + `retail.decoded.log` were grepped for
+`change_cell` / `curr_cell` / `find_cell_list` / `cell=0x` / `insert_into_cell`. **Zero matches in
+any retail log** — all 15,492 membership/cell-id matches are in the paired `acdream.log` files
+(our own probe output). The committed retail traces are collision-only (`find_collisions`
+hit-counters, `set_neg_poly_hit`, etc.); they carry no membership cell-id or position. So the
+retail-trace-backed threshold golden **cannot** be built from existing data — a live capture is
+required (`tools/cdb/find-cell-list-capture.cdb`).
+
+## P0 status / P1-entry checklist
+
+**Autonomous apparatus: COMPLETE + GREEN.** (Conformance suite 58 pass / 1 skip / 0 fail.)
+- ✅ Dat-backed fixture loader (`ConformanceDats`).
+- ✅ Characterized + pinned cottage-doorway topology (`0031↔0170↔0171` verified real).
+- ✅ `point_in_cell` goldens vs real dat BSP.
+- ✅ `find_cell_list` unambiguous goldens (interior picks + stale-seed re-pick stability).
+- ✅ Retail-trace parser (`RetailTrace`, 4 tests) + cdb capture script + README.
+- ✅ PVS-golden scaffold (skipped; filled in P4).
+- ⏳ `FindCellList_DoorwayThreshold_MatchesRetailTrace` — wired, **skips until the capture fixture
+  `Conformance/Fixtures/find-cell-list-threshold.log` exists**.
+
+**P0 gate for P1 (`≥1 retail-trace-backed assertion`): PENDING the one user-gated capture.**
+The existing traces don't satisfy it (collision-only). To meet the strict gate, run
+`tools/cdb/find-cell-list-capture.cdb` against live retail at the cottage doorway (its README is
+the runbook), decode, drop the log at the fixture path, and re-run the threshold test:
+- GREEN → acdream already matches retail at the threshold; P1's membership port preserves it.
+- RED → the P1 divergence, captured as a documents-the-bug conformance test (do not weaken).
+
+**Re-scope note for P1 (discovered during P0):** this branch already carries the membership
+"Stage 1" work the master plan's §2 "acdream now" column lists as partial — `CellArray` (ordered
+CELLARRAY / R1 flap fix), `FindCellSet`'s interior-wins pick (cites pc:308788-308825),
+`RunCheckOtherCellsAndAdvance` (collide-then-pick), swept `sp.CurCellId` return, player-only
+`UpdatePlayerCurrCell`. P1's REAL remaining scope is narrower: intrinsic building entry (delete
+`CheckBuildingTransit`) + uniform `find_env_collisions` (delete the `cellLow >= 0x0100` fork) +
+demote `ResolveCellId` to seed-only. Re-confirm against the code when P1 starts.
diff --git a/tests/AcDream.Core.Tests/Conformance/ConformanceDats.cs b/tests/AcDream.Core.Tests/Conformance/ConformanceDats.cs
index 1c056c1..197f937 100644
--- a/tests/AcDream.Core.Tests/Conformance/ConformanceDats.cs
+++ b/tests/AcDream.Core.Tests/Conformance/ConformanceDats.cs
@@ -40,6 +40,27 @@ public static class ConformanceDats
         return Directory.Exists(def) ? def : null;
     }
 
+    /// <summary>
+    /// The conformance fixtures dir in the SOURCE tree (mirrors
+    /// CellarUpTrajectoryReplayTests.FixtureDir — fixtures are read from source,
+    /// not copied to the output dir).
+    /// </summary>
+    public static string FixturesDir =>
+        Path.Combine(SolutionRoot(), "tests", "AcDream.Core.Tests", "Conformance", "Fixtures");
+
+    private static string SolutionRoot()
+    {
+        var dir = AppContext.BaseDirectory;
+        while (!string.IsNullOrEmpty(dir))
+        {
+            if (File.Exists(Path.Combine(dir, "AcDream.slnx")))
+                return dir;
+            dir = Path.GetDirectoryName(dir);
+        }
+        throw new InvalidOperationException(
+            "Could not locate AcDream.slnx from " + AppContext.BaseDirectory);
+    }
+
     /// <summary>The physics-verbatim cell→world transform (no +2cm render lift).</summary>
     public static Matrix4x4 WorldTransform(DatEnvCell datCell) =>
         Matrix4x4.CreateFromQuaternion(datCell.Position.Orientation) *
diff --git a/tests/AcDream.Core.Tests/Conformance/FindCellListConformanceTests.cs b/tests/AcDream.Core.Tests/Conformance/FindCellListConformanceTests.cs
index 8d09c0c..e14add6 100644
--- a/tests/AcDream.Core.Tests/Conformance/FindCellListConformanceTests.cs
+++ b/tests/AcDream.Core.Tests/Conformance/FindCellListConformanceTests.cs
@@ -84,4 +84,33 @@ public class FindCellListConformanceTests
             CottageDoorwayCharacterizationTests.Room0171); // stale/wrong seed
         Assert.Equal(CottageDoorwayCharacterizationTests.Vestibule0170, picked);
     }
+
+    /// <summary>
+    /// THE retail-trace-backed golden (P0 gate for P1). For each captured retail
+    /// find_cell_list pick at the doorway threshold, assert acdream's FindCellList
+    /// returns the SAME cell for the SAME (seed, position). Skips until the capture
+    /// fixture exists (see tools/cdb/find-cell-list-capture.cdb). If it FAILS once
+    /// the fixture is in place, that is the P1 divergence — leave it RED, do NOT
+    /// weaken the assertion (master plan §4).
+    /// </summary>
+    [Fact]
+    public void FindCellList_DoorwayThreshold_MatchesRetailTrace()
+    {
+        var datDir = ConformanceDats.ResolveDatDir();
+        if (datDir is null) return;
+        var fixturePath = System.IO.Path.Combine(ConformanceDats.FixturesDir, "find-cell-list-threshold.log");
+        if (!System.IO.File.Exists(fixturePath)) return; // gate not yet satisfied — capture pending
+
+        using var dats = new DatCollection(datDir, DatAccessType.Read);
+        var cache = LoadThresholdBuilding(dats);
+
+        var picks = RetailTrace.ParseAll(System.IO.File.ReadAllLines(fixturePath));
+        Assert.NotEmpty(picks); // a present-but-unparseable fixture is itself a failure
+
+        foreach (var pick in picks)
+        {
+            uint ours = CellTransit.FindCellList(cache, pick.Position, FootRadius, pick.SeedCellId);
+            Assert.Equal(pick.PickedCellId, ours);
+        }
+    }
 }
diff --git a/tests/AcDream.Core.Tests/Conformance/Fixtures/README.md b/tests/AcDream.Core.Tests/Conformance/Fixtures/README.md
new file mode 100644
index 0000000..3afeca8
--- /dev/null
+++ b/tests/AcDream.Core.Tests/Conformance/Fixtures/README.md
@@ -0,0 +1,11 @@
+# Conformance fixtures
+
+Captured retail golden data for the P0 conformance tests.
+
+- `find-cell-list-threshold.log` — **pending capture.** Retail `find_cell_list` picks at the
+  Holtburg cottage doorway, in the `[fcl] seed=0x.. px=.. py=.. pz=.. picked=0x..` format read by
+  `RetailTrace.ParseFindCellList`. Produced by `tools/cdb/find-cell-list-capture.cdb` (see its
+  README). Until it lands, `FindCellList_DoorwayThreshold_MatchesRetailTrace` skips.
+
+Fixtures are read from this SOURCE directory (via `ConformanceDats.FixturesDir`), not copied to
+the build output — matching the existing `Fixtures/issue98/**` pattern.
diff --git a/tests/AcDream.Core.Tests/Conformance/PvsConformanceTests.cs b/tests/AcDream.Core.Tests/Conformance/PvsConformanceTests.cs
new file mode 100644
index 0000000..a11718e
--- /dev/null
+++ b/tests/AcDream.Core.Tests/Conformance/PvsConformanceTests.cs
@@ -0,0 +1,24 @@
+using Xunit;
+
+namespace AcDream.Core.Tests.Conformance;
+
+/// <summary>
+/// PVS (portal-visibility) conformance — P0 scaffold. The render visible-set
+/// golden. Retail oracle: PView::ConstructView(CEnvCell*) @ 0x005a57b0
+/// (pc:433750) produces the ordered cell_draw_list for a given (viewer_cell,
+/// eye); see docs/research/2026-06-02-retail-render-pipeline-full-reference.md §3.
+///
+/// FILLED IN P4, not P0: a retail cell_draw_list trace is a P3/P4-coupled
+/// capture (a new cdb script breakpointing PView::DrawCells / cell_draw_list,
+/// sibling to find-cell-list-capture.cdb), and the PVS code itself
+/// (PortalVisibilityBuilder) is REPLACED by the ConstructView port in P4. The
+/// scaffold exists now so the structure + retail anchor are in place; P4 adds
+/// the capture + the golden assertion (PVS root id == physics CurrCell.Id;
+/// a cell seen through two portals appears once per slice; dungeon
+/// outside_view==0).
+/// </summary>
+public class PvsConformanceTests
+{
+    [Fact(Skip = "P0 scaffold — filled in P4 with a captured retail cell_draw_list trace")]
+    public void Pvs_CottageInterior_MatchesRetailCellDrawList() { }
+}