docs(runtime): close simulation ownership

docs/research/2026-07-26-slice-j5-7-simulation-ownership-closeout.md

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+# Slice J5.7 — simulation-ownership closeout
+
+Date: 2026-07-26
+Scope: ownership and teardown cleanup only; no retail algorithm, packet,
+timing, collision policy, gameplay outcome, or graphical presentation change
+
+## Objective
+
+Close the temporary seams left by J5.1–J5.6 so one Runtime lifetime owns the
+complete presentation-independent simulation graph:
+
+- canonical entity/object identity and accepted wire state;
+- selection, interaction, combat, magic, and local movement intent;
+- per-session physics, remote motion, projectiles, shadows, and spatial
+  worksets;
+- reset, projection withdrawal, and terminal retirement.
+
+App remains the graphical host. It supplies physical input, immutable
+DAT/content inputs, transport and projection acknowledgements, then presents
+committed Runtime state through animation, meshes, particles, audio, cameras,
+retained UI, markers, and diagnostics.
+
+## Named-retail invariant
+
+J5.7 preserves the already-ported retail control flow. The one relocated
+initialization detail follows:
+
+- `CPhysicsObj::set_description` at `0x00514F40`
+
+CreateObject velocity and angular velocity are installed once when Runtime
+constructs the canonical remote body. Later authoritative Vector updates flow
+through the existing retail timestamp gate and canonical record. App no longer
+constructs a second body or repeats the accepted CreateObject vector install.
+
+The projectile, movement, collision, interaction, combat, and spell algorithms
+remain those documented by the preceding J5 evidence notes. No constant,
+branch, packet order, server-authority boundary, or visible effect changed.
+
+## Closed ownership gaps
+
+Production commit
+`cdee7a4b49addb5e1500753f6a885f7c899bd0f0`:
+
+- removes the App remote-motion/physics-host/canonical-runtime/cell/placement
+  compatibility aliases after production consumers moved to Runtime types;
+- deletes `LiveEntityRemoteMotionRuntimeView<T>` and the App
+  `RemotePhysicsBodyInitializer`;
+- makes `LiveEntityNetworkUpdateController` borrow the canonical
+  `LiveEntityRuntime` and delegate body, remote-motion, vector, wakeup, and
+  activation work to `RuntimePhysicsState`;
+- makes Runtime install accepted CreateObject velocity and angular velocity
+  exactly once at canonical body construction;
+- makes `RuntimeEntityObjectLifetime.CompleteProjectionRetirement` own final
+  simulation-component retirement after the App projection acknowledges
+  withdrawal;
+- removes App-side mutation of canonical remote/body/host/placement component
+  slots;
+- makes current-runtime checkpoints borrow `IRuntimeEntityView` and inventory
+  views rather than reconstructing state from App projections or
+  `ClientObjectTable`;
+- adds terminal clearing for `PhysicsEngine`, `ShadowObjectRegistry`, spatial
+  worksets, collision residence, bodies, hosts, remotes, and projectiles;
+- adds `RuntimeSimulationOwnershipSnapshot`, one terminal ledger spanning
+  entity/object, physics, and gameplay ownership;
+- adds a Runtime-only fixture host that drives movement, use, combat, casting,
+  and projectile simulation without loading App, UI, Silk.NET, OpenAL, ImGui,
+  Arch, or a native window.
+
+`ILocalPlayerMotionSource` remains as a presentation-facing source name for
+the animation projection seam. It does not construct, store, or mutate a
+second movement owner; graphical animation borrows the exact
+`RuntimeLocalPlayerMovementState`.
+
+## Failure and parity matrix
+
+The closeout fixtures cover every J5.7 boundary:
+
+| Boundary | Evidence |
+|---|---|
+| construction | per-instance entity/object/physics/gameplay owners; canonical remote-body acquisition; no presentation/backend assembly load |
+| subscription | entity, communication, gameplay, and projection observers isolate failures and detach exactly |
+| command | graphical and direct movement, use, combat, and magic commands reach the same exact owners |
+| projection acknowledgement | vector, rebucket, projectile, and terminal projection failures preserve canonical committed state and allow retry/convergence |
+| reset | interaction, action, movement, session, entity/object, and physics reset paths converge without replay |
+| disposal | combined simulation ledger, physics residence, shadows, worksets, objects, and subscriptions reach exact zero |
+
+Normalized graphical/direct parity is pinned by:
+
+- `CurrentGameRuntimeAdapterTests.GraphicalAndDirectCombatMagicCommands_ReachTheExactSameOwners`;
+- `CurrentGameRuntimeAdapterTests.DirectAndGraphicalHosts_ProduceIdenticalEntityObjectTrace`;
+- `RuntimeLocalPlayerMovementStateTests.GraphicalAndDirectCommandsMutateOneAutorunLatch`;
+- `RuntimeSimulationFixtureHostTests.RuntimeOnlyHostDrivesCompleteJ5SimulationWithoutPresentation`.
+
+The projection-failure fixture additionally proves that a failed graphical
+acknowledgement cannot strand or roll back canonical simulation state:
+
+- `RuntimeSimulationFixtureHostTests.ProjectionAcknowledgementFailureStillAllowsTerminalConvergence`.
+
+## Automated acceptance
+
+On the production commit:
+
+- focused App ownership/entity/projectile/hydration suite: 198 passed;
+- Runtime tests: 323 passed;
+- App tests: 3,717 passed / 3 skipped;
+- complete Release solution: 8,596 passed / 5 skipped;
+- Release solution build: zero errors; 17 pre-existing warnings;
+- source/dependency guards pass;
+- `git diff --check` is clean.
+
+The combined Runtime fixture loads no presentation or backend assembly and
+its terminal `RuntimeSimulationOwnershipSnapshot.IsConverged` is true after
+normal operation and injected projection failure.
+
+## Connected acceptance
+
+Both accepted connected gates used the exact rebuilt executable and source
+commit `cdee7a4b49addb5e1500753f6a885f7c899bd0f0`.
+
+- Lifecycle/reconnect:
+  `logs/connected-world-gate-20260726-160825/report.json`
+  passed all seven fresh-login, outdoor, dungeon, revisit, graceful-disconnect,
+  and uncapped fresh-process reconnect checkpoints. Both processes exited
+  gracefully with code zero, with zero failures and only the 25 expected
+  world-edge empty-landblock misses.
+- Canonical nine-stop route:
+  `logs/connected-r6-soak-20260726-161406.report.json`
+  reported `binaryMatchesSource = true`, materialized all nine destinations,
+  passed forward, jump, combat, and authoritative movement-truth exercises at
+  Caul, Holtburg, and the Caul return, and exited gracefully with code zero
+  and zero failures. Every checkpoint converged with zero pending publication,
+  retirement, worker-completion, or destination backlog.
+
+The earlier post-commit route
+`logs/connected-r6-soak-20260726-155912.report.json` was behaviorally green
+but is deliberately rejected as exact-binary evidence because its embedded
+binary SHA preceded the source commit. It remains in the audit trail. The
+solution was rebuilt and both accepted gates were then rerun.
+
+The user-accepted connected behavior carried through J5 includes local
+movement and target-facing, near/far object use, combat and spell bars,
+projectile presentation, collision, repeated portal/recall, and reconnect.
+J5.7 changes only ownership seams and the exact-binary routes exercise those
+same owners after cleanup.
+
+## Divergence and rollback
+
+J5.7 removes duplicate ownership and compatibility seams. It introduces no
+new retail behavior or divergence, so the divergence register requires no new
+row.
+
+Exact rollback:
+
+```text
+git revert cdee7a4b49addb5e1500753f6a885f7c899bd0f0
+```