feat(runtime): C3c - production placement cutover: both hosts on the residence conductors (routes 1+8)

Campaign P remaining-physics-divergence, placement cutover slice C3c
(docs/plans/2026-08-02-placement-cutover.md). Both production hosts now
register every initial Create through the residence + continuation-
executor + first-entry-conductor machinery (C0-C3b):

- Graphical (route 1): RegisterEntityWithInitialResidence at Create; the
  shared RuntimeFirstEntryDriveController pumps both conductors from the
  placement-receipt flow; MaterializeProjection and RebucketLiveEntity
  are presentation-only while a residence is ACTIVE (ExecutorCompleted is
  the presentation-binding receipt); post-residence entities take the
  full legacy path including the prepare_to_enter_world clock edges.
  PlayerModeController attaches presentation to the Runtime-published
  controller; its legacy resolve/step-heights/host-construction path is
  deleted; presentation-only rollback (retail has no entry-flow rollback).
- Headless (route 8): OnSpawned registers with residence when a drive
  exists; content-less sessions keep the pre-flip direct registration;
  SynchronizeLocalPlayer/CreateController/ApplySetupStepHeights deleted;
  prepared-collision read failure is a typed AwaitingCollisionSource
  retry; far remotes outside the service window complete celless.
- RuntimeLocalPlayerMovementState.Controller setter sealed internal; all
  controller mutation flows through the publication lifecycle.

Fix slices landed within this cutover, each dual-gated:
- F1: live movement-stat/server-physics application routed through the
  Runtime ownership seam (post-logout ingest crash on the retired
  controller eliminated; RuntimeMovementSkillProjection deleted).
- F2: login activation wedge - collision-admission prefix gate factored
  out of the seal (reentrant-commit RejectedAuthority), rearm generation
  identity corrected, PlayerModeAutoEntry requires the Runtime-published
  controller (world reveal can no longer seal unmaterialized).
- F3: landblock-prefix 0-sentinel replaced by explicit absent-id guards;
  map-corner landblocks (grid row/col 0) fully legal through admission,
  park/rearm/retire, quiescence, and outdoor shadow seeds.
- F5: local-player first-entry ground contact seeded by the shared
  SpawnPlacementSettler (moved App->Core) at FinalizeActivation - the
  retail first-gravity-frame touch (enter_world 0x00516170 carries no
  seed); the legacy unconditional force-seed is overwritten by a real
  floor-found contact; airborne spawns stay airborne; outbound contact
  bit verified end-to-end. Fixes the standing-cast 'You can't do that
  while in the air!' rejections.
- R1 (dual-review round): login constraint leash armed at the committed
  placement (HandleReceivedPosition 0x00453FD0 analog); register rows
  AD-61 (settle-timing compression now covering the local player) and
  AD-42 (repointed off the deleted resolve split) in this commit;
  residence-conversion owner API; wire-landblock guards; drive-pending
  ledger in IsConverged; route attach/detach latch; executor-drain drift
  model documented + source-pinned.

Gates: Runtime 1,003, App 4,039/3 skips, Headless 79, complete solution
10,816/0 failed/4 skips (Release, -m:1); connected lifecycle/reconnect
gate PASS (logs/connected-world-gate-20260802-175401; graceful exits,
world-visible, zero airborne rejections). The nine-stop soak remains red
for the pre-existing 6b28ff99 whole-world collision-clone throughput
regression (attributed with evidence; scheduled as its own slice before
C5). Dual Opus reviews (retail-conformance + adversarial): delta PASS.

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

tests/AcDream.Core.Tests/Physics/ShadowObjectRegistryTests.cs

@@ -56,6 +56,29 @@ public class ShadowObjectRegistryTests
         Assert.Equal(1, reg.TotalRegistered);
     }
 
+    [Fact]
+    public void Register_CornerLandblock_DerivesRealOutdoorSeed()
+    {
+        // C3c-F3: landblock (0,0) — id 0x0000FFFF — has prefix 0x00000000.
+        // DeriveOutdoorSeed's prefix-0 "absent" sentinel used to reject it,
+        // silently dropping every landblock-baked static in the map-corner
+        // block. Local (12,12) = cell (0,0) = cellId 0x00000000 | 1.
+        var reg = new ShadowObjectRegistry();
+        reg.Register(1u, 0x01000001u, new Vector3(12f, 12f, 50f), Quaternion.Identity, 1f, OffX, OffY, 0x0000FFFFu);
+        Assert.Equal(1, reg.TotalRegistered);
+        Assert.Contains(reg.GetObjectsInCell(0x00000001u), e => e.EntityId == 1u);
+    }
+
+    [Fact]
+    public void Register_AbsentLandblockId_StillKeepsWhenEmpty()
+    {
+        // The genuine "no landblock" input (id 0) must keep the
+        // keep-when-empty behavior (retail pc:283540) the sentinel provided.
+        var reg = new ShadowObjectRegistry();
+        reg.Register(1u, 0x01000001u, new Vector3(12f, 12f, 50f), Quaternion.Identity, 1f, OffX, OffY, 0u);
+        Assert.Equal(0, reg.TotalRegistered);
+    }
+
     // -----------------------------------------------------------------------
     // GetObjectsInCell
     // -----------------------------------------------------------------------