Wrong Yellow Matrix V2.5 — scheduler and controller-ticket repair

Grounded defects fixed from V2.4:

1. build/process compared every command against the live br_giga_step score.
   Every step incremented that same score, so later lines matched immediately.
   A complete macrocell could therefore execute almost all of its 108 build steps in one server tick.

2. The segment at local offset 0 used the same chunk as the persistent macrocell marker.
   Its final layer removed that forceload ticket before the macrocell was complete.
   With a real two-tick scheduler, a remote builder could unload and stop unless a player approached it.

3. Caps are two blocks thick and straddle macrocell/chunk boundaries.
   V2.4 loaded only the chunk containing the cap origin. V2.5 loads both touched chunks.

V2.5 behavior:
- immutable step snapshot, exactly one build operation every 2 server ticks;
- persistent centre controller ticket until macrocell completion;
- temporary one-chunk tickets for 16-block split slices;
- temporary two-chunk tickets for caps;
- periodic self-healing of unfinished split-network markers;
- completed network lock tags are removed automatically;
- unused cap/cross phases are skipped instead of consuming silent two-tick slots;
- runtime marker version 6 clears stale V2.4 jobs while matrix plan version 4 is preserved.
