# Slice K3 shared-content and isolation checkpoint

**Date:** 2026-07-27
**Status:** Automated checkpoint complete; connected Windows/Linux gate remains
**Commits:** `12b500d3`, `9569dadb`, `b6547ff3`

## Outcome

The production headless process now opens DAT and `acdream.pak` content once,
leases the exact owner to every configured session, and disposes the mapping
only after the final lease. Sessions share immutable magic/catalog, terrain
height, and bounded flat-collision payloads while retaining distinct
`GameRuntime`, entity, object, action, movement, physics-engine, data-cache,
scratch, and teardown owners.

The direct inbound route now projects accepted local-player spawn/position and
portal state into one per-session movement controller and a per-session
collision neighborhood. Terrain, EnvCell topology, buildings, stabs, and
retail-generated scenery use the same presentation-free content builder as the
graphical streaming path. Headless hydration deliberately skips visual bounds,
so it does not populate the graphical process-wide `GfxObjBounds` cache.

The scheduler quarantines a throwing policy, detaches it before canonical
teardown deltas, and continues healthy sessions. Headless startup rejects
process-global physics probes whose mutable capture cursors cannot be
attributed safely across sessions.

## Automated evidence

- Runtime tests: 412 passed.
- Headless tests: 42 passed.
- App tests: 3,722 passed / 3 skipped.
- Complete Release solution: 8,758 passed / 5 skipped.
- Streaming/collision focused gate: 277 passed.
- Parameterized 1/5/10-session gate:
  - identical server GUIDs remain isolated;
  - activity and portal completion remain per Runtime root;
  - reconnect replaces only that session's incarnation/generation;
  - every teardown ledger converges.
- Policy-fault gate: one failing policy is quarantined while the healthy
  session continues ticking.
- Shared-content gate: exact DAT, package, magic catalog, height-table backing
  array, and bounded collision source are shared; mutable physics/cache/
  movement owners are not.

## Remaining K3 gate

1. Run the production Release executable against local ACE in a visible
   terminal with no window, renderer, audio, or UI assemblies.
2. Observe initial collision hydration, lifestone recall, reconnect, and exact
   final content-lease disposal.
3. Repeat the production gate on Linux/WSL.
4. Add the connected resource evidence and close K3 before deriving K4's
   numeric 1/5/10/30-session ceilings.

## Exact rollback

Newest first:

```text
git revert b6547ff38c375328417855200f41c8af6436f246
git revert 9569dadb578b299b24e30aec85eee86ec0c2b3fb
git revert 12b500d38362e8aae0a23a4f9712b86367006f76
```