Garrison laser vessels and gas bombers, on a shared ability seam

#105 shipped with interceptors as the only garrisonable vessel, and the
reason was a design fault rather than a decision: firing the laser and the
gas bomb lived in the player's fleet controllers, so a stationed laser would
have held its position and never shot.

The shot is now a thing in the world rather than something a controller
draws. LaserBeamEffect and GasBombEffect are self-contained, self-animating
and self-freeing, added to the tree root - the same shape EnemyBigLaserBeam
and ArtilleryShell already had on the enemy side - and they outlive the
vessel that fired them.

Above them sits one seam, on VesselCooldownFillComponent: ability_range(),
ability_ammo_resource(), ability_ammo_cost() and fire_ability(). A beam and a
bomb are now the same shape of thing to whoever pulls the trigger, so the
garrison AI never names an ability - the test asserts that literally, by
reading the AI's own source. A third armed vessel needs to implement the
seam and nothing else.

Ammunition is the CALLER's business, deliberately: the fleet spends from its
hold, a garrison from its outpost's store, and neither concern belongs in
the component. A garrison with an empty magazine holds fire rather than
falling back on the fleet's hold.

Outpost storage: 50 gas per stationed bomber and 50 energy per stationed
laser, off the VESSEL definitions, so an outpost never learns which vessel
needs what. It is a capacity, not a stock - hub transporters fill it exactly
as they fill a gas burner's buffer, because building_logistics_deficit now
takes the larger of the definition's static buffer and the garrison's
magazine. Every other resource is capped at zero: an outpost is not a depot,
and ore parked at one has nothing to do there and no transporter coming for
it.

Also restores two properties the Godot editor dropped from
GasBurnerBuildingDefinition.tres when it re-saved the file:
collected_outputs and capabilities. Without the first, nothing ever collects
the burner's energy - test_gas_burner caught it.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

vessels/VesselLaserComponent.gd

@@ -22,6 +22,29 @@ func apply_stats() -> void:
 	queue_redraw()
 
 
+# #90/#103 follow-up: the beam is a LaserBeamEffect in the world, not
+# something the fleet's controller draws. See the class comment there.
+const BEAM_EFFECT = preload("res://vfx/LaserBeamEffect.gd")
+# What one shot costs, and how much a garrisoned laser keeps beside it. Data
+# on the component rather than in the controller: a garrison spends the same
+# ammunition through a different trigger.
+const ENERGY_PER_SHOT: int = 8
+
+
+func ability_range() -> float: return beam_range
+func ability_ammo_resource() -> String: return GameState.RESOURCE_ENERGY
+func ability_ammo_cost() -> int: return ENERGY_PER_SHOT
+
+
+func fire_ability(world: Node, origin: Vector2, at: Vector2) -> bool:
+	if not consume_shot():
+		return false
+	var direction: Vector2 = at - origin
+	# A beam always reaches full range; the aim chooses its direction only.
+	BEAM_EFFECT.fire(world, origin, direction, beam_range, damage)
+	return true
+
+
 func consume_shot() -> bool:
 	return _begin_cooldown(cooldown_duration)