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.Runtime/Entities/RuntimeInitialCreateResidenceState.cs

@@ -1007,6 +1007,52 @@ internal sealed class RuntimeInitialCreateResidenceState
         return _completed.Remove(token.Entity);
     }
 
+    /// <summary>
+    /// C3c-R1 review F7: converts an ACTIVE, not-yet-placed
+    /// SetPosition-performing residence to the celless
+    /// (AwaitFreshPosition) route shape, forgetting its authored placement
+    /// operation. The residence entry itself stays active — the conductor's
+    /// next pump takes the existing celless skip-to-Execute path and
+    /// completes with FullCell 0, exactly like a Parented/PickedUp lease.
+    /// The retirement fan-out is fired to reset conductor/executor progress
+    /// for the key (its subscribers are pure progress reapers:
+    /// executor <c>DiscardProgress</c> + both conductors' <c>Forget</c>);
+    /// the entry itself is deliberately NOT retired. Refused once any
+    /// placement has committed (<c>FullCellId != 0</c>) — the entity is not
+    /// a far remote then.
+    /// </summary>
+    internal bool TryConvertToCellessRoute(RuntimeEntityRecord record)
+    {
+        ArgumentNullException.ThrowIfNull(record);
+        if (record.Key is not { } key
+            || !_entries.TryGetValue(key, out Entry? entry)
+            || !ReferenceEquals(entry.Record, record))
+        {
+            return false;
+        }
+        if (!IsCurrent(entry))
+        {
+            Retire(entry);
+            return false;
+        }
+        RuntimeInitialCreateResidenceLease lease = entry.Lease;
+        if (!lease.Route.PerformsSetPosition)
+            return true;
+        if (record.FullCellId != 0u)
+            return false;
+        RuntimePlacementCancellationReceipt cancellation =
+            _setPosition.ForgetExactPlacement(lease.Placement);
+        entry.Lease = lease with
+        {
+            Route = RuntimeAuthoritativePositionRouteClassifier
+                .ToCellessCreateRoute(lease.Route),
+            Placement = default,
+        };
+        _setPosition.PublishCancellation(cancellation);
+        NotifyRetirement(key);
+        return true;
+    }
+
     internal bool Forget(
         RuntimeEntityRecord record,
         out RuntimeInitialCreateResidenceLease lease,