probe(render): cathedral Phase I instrumentation

Implements the synthesis plan''s Phase I (instrument-first, no rendering
edits): the [falls] watch printing EVERY particle submission carrying a
real falls owner (the outdoor landblock emitters 0xCF418000-13 the six
fix rounds never traced) with route + phase; [falls-adm] admission
verdicts for F418 emitters at the retail ShouldDrawParticles port
(owner, cell, distance, in-set, eligibility); the continuous
[walk-root] line now separating the TRUE root flood
(InteriorFloodCells) from the visited union (root + look-ins - the
conflation the review corpus indicted) and printing the walk''s own
exit-view count; [walk-cam] replayable camera dumps; and the restored
[walk-portal] per-portal side/clip decisions. All under the existing
ACDREAM_PROBE_WALK_ROOT flag; the depth-checkpoint readback is
deferred until these answers narrow the question (mid-pass Vulkan
depth reads need render-pass splitting).

Hermetic 6,762/0.

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

src/AcDream.App/Rendering/RetailPViewPassExecutor.cs

@@ -639,6 +639,29 @@ internal sealed partial class RetailPViewPassExecutor :
                 sb.Append(id.ToString("x"));
             }
             ids = $" n={owners.Count} ids=[{sb}]";
+
+            // Phase I cathedral instrumentation: the REAL falls owners
+            // (outdoor landblock statics 0xCF418000-13 per the DAT-geometry
+            // report) — print EVERY submission that carries one, with the
+            // exact watched ids, unconditionally (never rate-limited; these
+            // are the money lines the six fix rounds never had).
+            System.Text.StringBuilder? falls = null;
+            foreach (uint id in owners)
+            {
+                if (id >= 0xCF418000u && id <= 0xCF418014u)
+                {
+                    falls ??= new System.Text.StringBuilder();
+                    if (falls.Length > 0) falls.Append(',');
+                    falls.Append(id.ToString("x"));
+                }
+            }
+            if (falls is not null)
+            {
+                Console.WriteLine(
+                    $"[falls] route={route} phase="
+                    + $"{AcDream.Core.Rendering.RenderingDiagnostics.WalkRootPhase} "
+                    + $"ids=[{falls}]");
+            }
         }
         Console.WriteLine(
             $"[walk-part] {route}{ids} phase={AcDream.Core.Rendering.RenderingDiagnostics.WalkRootPhase}");