docs(headless): close K3 connected gates

memory/project_modern_runtime_headless.md

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+# Modern Runtime headless continuation
+
+## Current checkpoint
+
+Slice J is closed. Slice K0-K3 are closed; K4 is active.
+
+K3's production closeout commit is `3f340125`. Its automated predecessors are
+`12b500d3`, `9569dadb`, and `b6547ff3`.
+
+The Windows visible-terminal host and native Linux/WSL host both connected to
+local ACE without loading presentation assemblies. Linux completed the
+Aerlinthe/Caul/Rynthid/lifestone route, accepted external `teleallto`
+destinations, remained visible to a retail observer, turned and ran smoothly,
+and shut down through ACE-confirmed graceful logout. The user accepted the
+observer movement gate on 2026-07-27.
+
+## Important connected correction
+
+`RuntimeLiveEntitySessionController` passes the exact accepted
+`PositionTimestampDisposition` to the direct world projection.
+
+- Normal `Apply` echoes update canonical state but do not reset the local
+  headless movement controller.
+- `ForcePosition` uses `BlipPosition`, preserves active movement semantics, and
+  sends an immediate autonomous-position acknowledgement.
+- A real teleport performs one full synchronization from
+  `PrepareDestination`.
+
+Do not reintroduce full local-player synchronization for every accepted
+Position packet; it stops movement and causes retail observers to see repeated
+run/snap-back rubberbanding.
+
+Collision `[snap]` output is high volume and must remain behind the explicit
+`PhysicsEngine.DiagnosticLog` sink.
+
+## Automation seam
+
+Graphical automation and headless policies use `IGameRuntimeView`,
+`IGameRuntimeCommands`, `IRuntimeEventSource`, and the same
+`RuntimeLocalPlayerFrameController`/outbound serializers. The route and
+observer policies are diagnostic consumers, not a second bot world or
+movement implementation.
+
+The user requires optional direct single-session CLI launch with
+`-user`/`-password` or the long-form aliases. Multi-session configuration
+continues to use credential providers.
+
+## Next work
+
+Execute K4 from `docs/plans/2026-07-26-modern-runtime-slice-k.md`:
+
+1. capture reproducible 1/5/10-session warm resource baselines;
+2. derive and commit numeric per-session/process ceilings;
+3. build the 30-session connected stress configuration and workload;
+4. run the two-hour Linux soak with recurring movement, use, combat/cast,
+   chat, portal, cancellation, and reconnect;
+5. prove stable final-hour plateaus and exact teardown convergence;
+6. close Slice K, then start Slice L Linux graphical/platform work.
+
+Final K3 automated counts: Runtime 412, Headless 47, App 3,722 / 3 skips,
+complete Release 8,764 / 5 skips.
+
+K3 connected-closeout rollback:
+
+```text
+git revert 3f3401257c83bdd9f557eb577ba08cf2e5ec9a06
+```