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>

src/AcDream.Headless/Hosting/HeadlessRuntimePlacementProjectionSink.cs

@@ -34,23 +34,39 @@ internal sealed class HeadlessRuntimePlacementProjectionSink
         if (projection.Kind is RuntimePlacementProjectionKind.ExecutorCompleted)
         {
             // F1: acknowledge-and-ignore, same as Discard - ExecutorCompleted
-            // is not a placement to project (no world/presentation mutation
-            // by definition; the executor's own drain already committed
-            // every Place/Withdraw this receipt follows). It must NOT fall
-            // through to the record-lookup gate below: that gate can validly
-            // reject an unrelated entity/session mismatch, and this sink's
-            // caller (RuntimePlacementProjectionSubscription) treats a false
-            // return as "leave at the FIFO head" - a rejected ExecutorCompleted
-            // would permanently wedge the entire ordered placement stream
-            // behind it. Currently provably inert: PublishExecutorCompletion
-            // has zero production callers (Execute/RegisterEntityWithInitialResidence
-            // are both unreached in production) - see
-            // HeadlessSessionHostTests.ExecutorCompletedReceiptIsAcknowledgeOnlyRegardlessOfRecordValidity.
+            // is not a placement to project (a headless host has no
+            // presentation to bind off the completed initial drain; the
+            // executor's own drain already committed every canonical fact).
+            // It must NOT fall through to the record-lookup gate below: that
+            // gate can validly reject an unrelated entity/session mismatch,
+            // and this sink's caller (RuntimePlacementProjectionSubscription)
+            // treats a false return as "leave at the FIFO head" - a rejected
+            // ExecutorCompleted would permanently wedge the entire ordered
+            // placement stream behind it.
             return true;
         }
 
         RuntimePlacementProjectionToken token = projection.Token;
         RuntimeEntityDirectory directory = _runtime.EntityObjects.Entities;
+        if (projection.Kind is RuntimePlacementProjectionKind.Place
+            or RuntimePlacementProjectionKind.Withdraw
+            && token.IsValid
+            && directory.TryGetByLocalId(
+                token.Entity.LocalEntityId,
+                out RuntimeEntityRecord residenceCandidate)
+            && directory.IsCurrent(residenceCandidate)
+            && residenceCandidate.Key == token.Entity
+            && _runtime.EntityObjects.TryGetInitialCreateResidence(
+                residenceCandidate,
+                out _))
+        {
+            // C3c: a Place/Withdraw for an entity still holding its
+            // initial-create residence belongs to the first-entry conductor
+            // machinery, which acknowledges its own receipts at the exact
+            // FIFO head. Leave it there for the drive pump; validating or
+            // acknowledging it here would starve the conductor forever.
+            return false;
+        }
         if (!token.IsValid
             || token.SessionLifetimeVersion
                 != directory.SessionLifetimeVersion