docs(runtime): close gameplay-state ownership

Record J4.5 canonical shortcut and spellbook command ownership, combined failure and graphical/headless parity evidence, the 8,544-test Release gate, exact-binary lifecycle and nine-stop acceptance, rollback instructions, and the J5 boundary.

Co-authored-by: Codex <noreply@openai.com>

docs/research/2026-07-26-slice-j4-5-gameplay-state-closeout.md

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+# Modern runtime J4.5 — gameplay-state closeout
+
+**Status:** COMPLETE
+**Production commit:** `89e6b207f81946b40c38c8dc6597817ad99fc6e0`
+**Parent plan:** `../plans/2026-07-26-modern-runtime-slice-j4.md`
+
+## Result
+
+J4 now has one presentation-independent owner for every gameplay-state group
+in its scope. Graphical UI, current-runtime/plugin projections, and future
+no-window hosts borrow the exact Runtime instances.
+
+- `RuntimeInventoryState` owns the one 18-slot `ShortcutStore` and the one
+  inventory transaction/busy owner over J3's canonical `ClientObjectTable`.
+- `RuntimeCharacterState` owns favorite spells, spellbook filters, and desired
+  component levels on its exact `Spellbook`.
+- Retained toolbar and spell controllers initiate typed Runtime commands; they
+  no longer construct or reconstruct another mutable shortcut, favorite, or
+  component collection.
+- `ItemInteractionController` requires the Runtime-owned
+  `InventoryTransactionState`; its compatibility fallback and ownership flag
+  are deleted.
+- One allocation-free `RuntimeGameplayOwnershipSnapshot` covers inventory,
+  character, and communication owner/subscriber convergence.
+
+The command seam preserves the named-retail local/send order:
+
+- toolbar shortcut add/remove sends first and then mutates `PlayerModule`;
+- favorite add/remove and filter changes mutate locally before sending;
+- desired-component set/clear sends first and then mutates locally;
+- an explicit desired-component value of zero remains an entry until the
+  complete list is cleared.
+
+The retail trace and pseudocode are recorded in
+[`2026-07-26-slice-j4-5-retail-local-command-order.md`](2026-07-26-slice-j4-5-retail-local-command-order.md).
+
+## Failure and parity evidence
+
+- Graphical command adapters and direct no-window owner commands produce equal
+  inventory/character snapshots, revisions, shortcuts, favorites, filters,
+  and desired-component values.
+- Invalid and stale-generation commands neither publish nor mutate.
+- Outbound exceptions preserve retail's already-committed local side of each
+  operation.
+- A failing UI/subscriber callback cannot skip another observer or strand a
+  half-disposed Runtime root. Terminal disposal reports the failure only after
+  every owned suffix has run and the combined ledger has converged.
+- Two independent Runtime graphs remain isolated and Runtime's dependency
+  closure loads no App, UI, Silk.NET, OpenAL, Arch, or ImGui assembly.
+
+## Automated evidence
+
+- Runtime suite: 175 passed.
+- App suite: 3,780 passed / 3 established skips.
+- Core suite: 3,306 passed / 2 established skips.
+- Core.Net suite: 600 passed.
+- UI abstractions: 545 passed.
+- Content: 119 passed.
+- Bake: 15 passed.
+- CLI: 4 passed.
+- Complete Release solution: 8,544 passed / 5 established skips.
+- Final incremental Release build: zero warnings and zero errors.
+- `git diff --check`: pass.
+
+## Exact-binary connected evidence
+
+`logs/connected-world-gate-20260726-095654/report.json` passed on exact source
+and embedded binary
+`89e6b207f81946b40c38c8dc6597817ad99fc6e0`:
+
+- six capped login/outdoor/dungeon/facility/revisit checkpoints;
+- one fresh-process uncapped reconnect checkpoint;
+- 247.294-second capped route and 61.424-second reconnect route;
+- both clients exited gracefully with code zero;
+- zero failures, render-shadow mismatches, pending deltas, or stranded owner
+  work.
+
+`logs/connected-r6-soak-20260726-100235.report.json` passed on the same exact
+source/binary commit:
+
+- all nine Caul/Sawato/Rynthid/Aerlinthe/Holtburg/revisit/plateau checkpoints;
+- camera-turn samples at every location and movement/jump/combat exercises at
+  Caul, Holtburg, and Caul return;
+- 515.083 seconds, graceful code-zero exit, zero failures, and
+  `BinaryMatchesSource=true`.
+
+Its six warnings are the established live-world diagnostics: small
+authoritative/transient entity, particle, script, and retained cache
+differences at the Caul plateau, 32 missing DAT VFX messages, and 25 expected
+world-edge empty-landblock misses. None is a J4 ownership failure.
+
+An earlier post-commit run was deliberately discarded before acceptance when
+the soak harness proved its executable still carried the prior commit stamp.
+The retained gates above ran only after a clean App rebuild and exact
+source/binary identity verification.
+
+## Divergence audit
+
+J4.5 changes ownership and faithfully ports existing local command ordering.
+It introduces no gameplay approximation, asynchronous command queue, or
+presentation difference. No divergence-register row was added or retired.
+
+## Rollback
+
+```text
+git revert 89e6b207f81946b40c38c8dc6597817ad99fc6e0
+```
+
+Revert J4.5 before J4.4 when unwinding gameplay-state extraction. Do not
+revert J3's canonical entity/object lifetime to mask a J4 command or teardown
+failure.
+
+## Next boundary
+
+J5 moves presentation-free movement, physics, selection/approach/use, combat
+intent, projectiles, and outbound cadence by coherent lifetime groups. Camera,
+input devices, selection graphics, combat/spell bars, animated poses, sound,
+particles, and all retained UI remain in App.