Build 27519a6

disguised spies can use enemy dispensers before sapping

New utility BOT_UTIL_SPY_USE_ENEMY_DISP: when a disguised
spy is near an enemy dispenser and needs health/ammo,
it navigates to the dispenser and waits there before
sapping. Enemy dispensers heal disguised spies since
they appear as teammates.

Utility score: 1000/distance + 0.5 (health bonus). Beats
sap-dispenser utilities at typical combat ranges. Spy
heals at enemy dispenser → full HP → utility drops →
sap-dispenser utility fires → spy saps.

Condition: spy class, disguised, unsapped dispenser,
not under construction, needs health or ammo, not
already in a sap schedule.