WRONG YELLOW MATRIX V2.7 — CENTRAL QUEUE

Root cause fixed:
V2.6 stored future split cells as marker entities in their own distant chunks.
When those chunks unloaded, the scheduler could no longer see the markers and
incorrectly considered the network finished. Approaching the missing branch
loaded those markers again and resumed it.

V2.7 architecture:
- One connected source-fence component is copied to persistent storage.
- Future cells are plain queue compounds: {x,z,cx,cz}.
- Only the current target is force-loaded and represented by a builder marker.
- The current step/delay/stall are mirrored into persistent global scores.
- /reload restores the current target and rewinds only its current vertical slice.
- Network completion is based on #wy_net_remaining, never distant entity selectors.

Runtime marker version: 8
Matrix plan version: 4 (unchanged)
