feat(runtime): bridge executor completion to the placement stream

Cutover slice C0 (docs/plans/2026-08-02-placement-cutover.md): the seam
work that lets C3 flip hosts onto a complete receipt stream instead of
growing one mid-cutover. The executor's Released exit now publishes an
acknowledge-only ExecutorCompleted receipt through the one placement
projection stream — registered before observer dispatch, correlated to
the full execution receipt, reaped exactly once on acknowledgement/
discard/session-clear, and counted in the convergence ledger. All three
production placement sinks acknowledge-and-ignore the new kind via early
returns proven behavior-preserving for every existing kind; without them
the first such receipt at cutover would permanently wedge the exact-head
FIFO behind sinks that return false. Provably inert today: the publisher
has no production caller.

Execute's live inputs now derive from Runtime's own owners bound at
GameRuntime construction: UsePositionFromServer is retail's exact
autonomy_level != 2 (CommandInterpreter::UsePositionFromServer
0x006B3B40, startup-only knob), and PlayerDistance uses the live movement
controller's position with a null-safe fallback to the caller struct —
never a fabricated origin. TryPrepareAndSubmitAuthoredPlacement chains
the prepared-collision Setup read through PrepareMover to submission with
zero validation-semantics changes. TryCommitParent and CommitWithdrawal
gain the sibling cancellation flow (residence + ordinary placement
family); TryCommitParent deliberately omits LeaveWorld — retail's
set_parent performs its single gated leave_world (0x00515A90) and a
second would have no counterpart.

Not fully dormant: the two cancellation fixes change Runtime paths
production already calls (today as no-op-adjacent hardening, since
nothing upstream begins a residence yet); everything else is reachable
only by tests. Reviewed: retail-conformance PASS + architecture/
adversarial PASS after one fix round (sink wedge, completion-receipt
lifecycle, null-controller distance). Runtime 921/921; complete Release
solution 10,716 passed / 4 intentional skips.

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

tests/AcDream.Runtime.Tests/Gameplay/RuntimeCharacterStateTests.cs

@@ -340,6 +340,51 @@ public sealed class RuntimeCharacterStateTests
         Assert.False(state.CaptureOwnership().MovementSkillsAreReset);
     }
 
+    // ---------------------------------------------------------------
+    // C0-2: retail CommandInterpreter::autonomy_level/UsePositionFromServer
+    // ---------------------------------------------------------------
+
+    [Fact]
+    public void AutonomyLevel_DefaultsToFullAndMirrorsRetailUsePositionFromServer()
+    {
+        using var state = new RuntimeCharacterState();
+
+        Assert.Equal(RuntimeCharacterState.FullAutonomyLevel, state.AutonomyLevel);
+        Assert.False(state.UsePositionFromServer);
+        Assert.True(state.CaptureOwnership().AutonomyIsDefault);
+
+        Assert.True(state.TrySetAutonomyLevel(0u));
+        Assert.Equal(0u, state.AutonomyLevel);
+        Assert.True(state.UsePositionFromServer);
+        Assert.False(state.CaptureOwnership().AutonomyIsDefault);
+
+        Assert.True(state.TrySetAutonomyLevel(1u));
+        Assert.True(state.UsePositionFromServer);
+
+        // Retail's SetAutonomyLevel rejects anything above 2; the level and
+        // the derived UsePositionFromServer gate stay exactly as they were.
+        Assert.False(state.TrySetAutonomyLevel(3u));
+        Assert.Equal(1u, state.AutonomyLevel);
+
+        Assert.True(state.TrySetAutonomyLevel(RuntimeCharacterState.FullAutonomyLevel));
+        Assert.False(state.UsePositionFromServer);
+        Assert.True(state.CaptureOwnership().AutonomyIsDefault);
+    }
+
+    [Fact]
+    public void ResetSession_RestoresAutonomyLevelToFull()
+    {
+        using var state = new RuntimeCharacterState();
+        Assert.True(state.TrySetAutonomyLevel(0u));
+        Assert.True(state.UsePositionFromServer);
+
+        state.ResetSession();
+
+        Assert.Equal(RuntimeCharacterState.FullAutonomyLevel, state.AutonomyLevel);
+        Assert.False(state.UsePositionFromServer);
+        Assert.True(state.CaptureOwnership().AutonomyIsDefault);
+    }
+
     private static ActiveEnchantmentRecord MakeVitae(uint spellId, float val) =>
         new(
             spellId, LayerId: 0u, Duration: -1f, CasterGuid: 0u,