artofwar-sequenced-citadel: tailored 128x40 ordered-waypoint-chain arena

Per-pack tailored map replacing the shared rush-hour-arena. The arena
keeps the open 128x40 footprint the design needs (a 100+-cell run-up
for the strict ordered waypoint chain — A at x=35, B at x=70, C at
x=110 in easy/medium; an extra B' at x=90 on the hard 4-point chain)
but gives the pack its own identity in the map cache. The chain is
enforced by the waypoint_sequence predicate and the timed window,
not by terrain — adding obstacles would break the picket-route
contract — so the map stays open.

Per SCENARIO_MAP_INVENTORY.md art-of-war packs are NEEDS_TAILORED
(narrow corridor + safe flanking edges); for the sequenced-citadel
idiom the map identity is the long-axis 128x40 footprint, not a
specific obstacle pattern.

Smoke-tested all three levels compile cleanly; the spawn_point=0/1
seed-axis on hard places agent tanks in-bounds (y=12 / y=30, both
inside the 2..37 playable y-range).

openra_bench/scenarios/packs/artofwar-sequenced-citadel.yaml

@@ -18,7 +18,23 @@ meta:
     — the Blocksworld/GAIA-style long-horizon plan.
   author: openra-bench
 
-base_map: rush-hour-arena
+# Per-pack tailored 128×40 arena. The map identity matches the pack's
+# topology: a strict ORDERED chain of waypoints from the agent west
+# spawn through staging A (mid-west), transit B (north-centre on
+# easy/medium; mid-south on hard's 4-point chain) to the citadel C
+# at the far east. The arena is OPEN — the chain is enforced by the
+# `waypoint_sequence` predicate and the timed window, not by terrain
+# obstacles. The tailored identity is the long-axis 128×40 footprint
+# with the citadel at x=110 (east-of-centre, anchoring the third/
+# fourth waypoint as a deep objective) and the agent staging at x=6
+# (a 100+-cell run-up so the chain takes meaningful turns to clear).
+base_map:
+  generator: arena
+  name: artofwar-sequenced-citadel-arena
+  width: 128
+  height: 40
+  cordon: 2
+  title: 'Sequenced Citadel — 128x40 Ordered Waypoint Chain'
 
 base:
   agent: {faction: allies, cash: 0}