docs(runtime): close J1 contract gate

Record the exact-binary connected lifecycle/reconnect acceptance, synchronized active pointers, rollback, and durable evidence before session ownership moves in J2.

docs/plans/2026-07-24-modern-runtime-architecture.md

@@ -5,8 +5,9 @@
 **Status:** Slices A–I are complete. Flat-authoritative collision, zero-
 allocation resolve scratch, parsed-graph removal, connected correctness/
 lifetime acceptance, and Slice-I closeout landed 2026-07-25. Slices F–L were
-explicitly approved 2026-07-24. Slice J0's dependency-boundary preparation is
-complete without moving gameplay owners; J1 is the active execution point.
+explicitly approved 2026-07-24. Slice J0–J1 established the enforced Runtime
+boundary and the borrowed view/command/event seam without moving canonical
+gameplay owners; J2 is the active execution point.
 
 **Scope:** Reconcile and sequence the existing Modern Pipeline (`MP`) and
 Linux/headless (`LH`) tracks using the 2026-07-24 connected performance audit.
@@ -1271,7 +1272,7 @@ honest metrics + committed baselines        (A — exit criteria block C)
   -> delta GPU submission                   (G)
   -> residual frame cleanup                 (H-a, H-b, H-c)
   -> flat collision assets                  (I — COMPLETE)
-  -> presentation-independent runtime       (J — CURRENT at J1)
+  -> presentation-independent runtime       (J — CURRENT at J2)
   -> Linux/headless/multi-session           (K)
   -> evidence-gated GPU jobs                (L)
 ```