Mirrors #60's gas bomber ammunition exactly: ENERGY_PER_SHOT (8) drawn
from GameState.fleet_inventory before consuming the firing ship's
cooldown, the button's enabled rule requires affordability too, and an
unaffordable-but-otherwise-ready press still explains itself through a
new LaserStatus label rather than silently doing nothing.
Added two small generic GameState helpers this needed:
deposit_fleet_resource()/deposit_bank_resource(), counterparts to
#60's withdraw_fleet_resource() for resources (energy) with no
dedicated fleet_cargo/fleet_gas_cargo-style property. Along the way,
confirmed deposit_resource_to_building() on a "bank" building deposits
into that building's own per-record inventory, NOT bank_inventory
itself - only building_resource()/building_inventory() special-case
the "bank" capability to redirect there.
test_laser_vessel.gd (#58) updated to stock fleet energy first, since
shots are no longer free - same fix#60 required for the gas bomber's
own pre-existing tests. Also fixed test_laser_vessel.gd's own instance
of the bare-ClassName.CONST script-corruption trap (documented in
#60's commit): var skill: LaserController and a bare
LaserController.BEAM_HALF_WIDTH reference, mirrored into a local const
instead.
