Asteroids can be shot apart for the ore inside them

Asteroids were pure hazard: the only thing one could ever do was cost you a
ship. They now take damage like anything else and break open, dropping ore the
fleet can fly over and collect - the one resource reachable in open space
without conquering anything, and something for the new fire stick to do out
there.

Two ways to destroy one, deliberately not equivalent. Shot apart yields the
ore; flown into does not - the rock shatters against a hull rather than being
mined, and a ship or a shield charge has just been spent on it. Without that
split a shield vessel could farm asteroids by ramming them.

Asteroid.take_damage() matches Enemy's contract exactly, so every weapon that
already knew how to hurt an enemy hurts an asteroid through the same branch
rather than a second special case: bolts, the laser sweep, and the gas bomb's
blast all pick both groups up together.

Dropped ore carries the asteroid's own drift, so it reads as debris rather
than as a spawned pickup, and it expires after a minute. Rock grew an optional
lifetime for that, defaulting to 0 (never) so hand-placed surface rocks are
unchanged - a planet surface is bounded and authored, open space is not, and a
field shot up and abandoned would otherwise leak nodes for the session. Rock's
header note that asteroids and rocks are never on screen together is no longer
true and now says so; the hexagon-versus-lump shape language matters more now
that they sit side by side, not less.

Five weapon tests silenced the asteroid field but never cleared what it had
already placed. That was harmless while asteroids were untouchable and is not
any more - two of them assert exact hit counts, and a drifting rock in the
beam would have made those fail intermittently.

Suite 111/111.

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

tests/test_asteroid_mining.gd

@@ -0,0 +1,166 @@
+extends SceneTree
+
+# Headless gameplay test: run with
+#   godot --headless -s res://tests/test_asteroid_mining.gd
+# Asteroids used to be pure hazard - the only thing one could ever do was cost
+# you a ship. They can now be shot apart for the ore inside, which is the one
+# resource reachable in open space without conquering anything.
+#
+# Covers:
+#   A. an asteroid survives a hit it should survive, so "destructible" does
+#      not mean "evaporates on contact with anything"
+#   B. enough fire destroys it and leaves ore behind
+#   C. the ore is fetchable - flying a ship over it loads the fleet's hold,
+#      which is the whole point of dropping it
+#   D. ramming destroys the asteroid but yields NOTHING. Without that split a
+#      shield vessel could farm asteroids by flying into them
+#   E. dropped ore expires if nobody collects it, so a field that gets shot up
+#      and abandoned cannot leak nodes for the rest of the session; a
+#      hand-placed surface rock still lives forever
+
+var game_state: Node
+var main: Node
+var fleet: Node
+var asteroid: Node2D
+var stage: int = 0
+var elapsed: float = 0.0
+var hold_before: int = 0
+
+
+func _initialize() -> void:
+	game_state = root.get_node("GameState")
+	game_state.buildings.clear()
+	game_state.extractors.clear()
+	game_state.reset_progression()
+	main = load("res://Main.tscn").instantiate()
+	root.add_child(main)
+	current_scene = main
+	fleet = main.get_node("Fleet")
+
+
+func _spawn_asteroid(at: Vector2) -> Node2D:
+	var rock: Node2D = load("res://Asteroid.tscn").instantiate()
+	rock.position = at
+	main.add_child(rock)
+	return rock
+
+
+func _clear_sky() -> void:
+	for node in get_nodes_in_group("asteroids") + get_nodes_in_group("rocks") \
+			+ get_nodes_in_group("enemies") + get_nodes_in_group("player_projectiles"):
+		if is_instance_valid(node):
+			node.free()
+
+
+func _process(delta: float) -> bool:
+	elapsed += delta
+	match stage:
+		0:
+			if elapsed < 0.3:
+				return false
+			main.get_node("EnemySpawner").set_process(false)
+			main.get_node("AsteroidField").set_process(false)
+			_clear_sky()
+			fleet.spawn_ships(1, Vector2.ZERO, PackedStringArray([GameState.VESSEL_INTERCEPTOR]))
+
+			# --- A/B. it takes real damage, then breaks -------------------
+			asteroid = _spawn_asteroid(Vector2(4000.0, 0.0))
+			var hit_points: int = int(asteroid.hp)
+			if hit_points < 2:
+				return _fail("an asteroid dies to a single point of damage, so there is nothing to survive")
+			for i in range(hit_points - 1):
+				asteroid.take_damage(1)
+			if not is_instance_valid(asteroid) or asteroid.is_queued_for_deletion():
+				return _fail("the asteroid broke after %d of its %d hit points" % [hit_points - 1, hit_points])
+			print("asteroid survived %d of %d hit points" % [hit_points - 1, hit_points])
+
+			asteroid.take_damage(1)
+			if is_instance_valid(asteroid) and not asteroid.is_queued_for_deletion():
+				return _fail("the asteroid survived its full %d hit points" % hit_points)
+			stage = 1
+			elapsed = 0.0
+			return false
+		1:
+			# The drop is deferred - it is created from inside a signal, where
+			# the physics server refuses a direct add_child.
+			if elapsed < 0.2:
+				return false
+			var dropped: Array = get_nodes_in_group("rocks")
+			if dropped.is_empty():
+				return _fail("destroying an asteroid left no ore behind")
+			print("destroyed asteroid dropped %d ore node(s)" % dropped.size())
+
+			# --- C. the ore is fetchable ---------------------------------
+			hold_before = game_state.fleet_resource(GameState.RESOURCE_ORE)
+			var ship: Node2D = fleet.ships[0]
+			# Placed just clear of the ship rather than on top of it, so the
+			# rock's own drift has to bring it in - that pull is how a player
+			# actually collects one.
+			dropped[0].position = ship.global_position + Vector2(80.0, 0.0)
+			stage = 2
+			elapsed = 0.0
+			return false
+		2:
+			if elapsed < 1.5:
+				return false
+			var gained: int = game_state.fleet_resource(GameState.RESOURCE_ORE) - hold_before
+			if gained <= 0:
+				return _fail("flying over the dropped ore put nothing in the hold")
+			print("dropped ore collected into the fleet hold (+%d)" % gained)
+
+			# --- D. ramming yields nothing -------------------------------
+			_clear_sky()
+			hold_before = game_state.fleet_resource(GameState.RESOURCE_ORE)
+			asteroid = _spawn_asteroid(fleet.ships[0].global_position)
+			stage = 3
+			elapsed = 0.0
+			return false
+		3:
+			if elapsed < 0.5:
+				return false
+			if is_instance_valid(asteroid) and not asteroid.is_queued_for_deletion():
+				return _fail("an asteroid dropped onto a ship did not shatter against it")
+			if not get_nodes_in_group("rocks").is_empty():
+				return _fail("ramming an asteroid yielded ore - a shield vessel could farm them that way")
+			if game_state.fleet_resource(GameState.RESOURCE_ORE) != hold_before:
+				return _fail("ramming an asteroid changed the hold")
+			print("ramming shattered the asteroid and yielded nothing")
+
+			# --- E. abandoned ore expires, authored ore does not ----------
+			_clear_sky()
+			var abandoned: Node2D = load("res://Rock.tscn").instantiate()
+			abandoned.build_shape(1)
+			abandoned.lifetime = 0.4
+			# Far from every ship, or it would be collected rather than expire.
+			abandoned.position = fleet.get_centroid() + Vector2(9000.0, 0.0)
+			main.add_child(abandoned)
+			var authored: Node2D = load("res://Rock.tscn").instantiate()
+			authored.build_shape(2)
+			authored.position = fleet.get_centroid() + Vector2(9600.0, 0.0)
+			main.add_child(authored)
+			if authored.lifetime != 0.0:
+				return _fail("a plain rock has a lifetime of %.1f - surface rocks must live forever" % authored.lifetime)
+			stage = 4
+			elapsed = 0.0
+			return false
+		4:
+			if elapsed < 1.0:
+				return false
+			var survivors: Array = get_nodes_in_group("rocks")
+			var names: Array = []
+			for rock in survivors:
+				names.append(rock.name)
+			if survivors.size() != 1:
+				return _fail("expected only the authored rock to remain, found %d: %s" % [survivors.size(), str(names)])
+			print("abandoned ore expired; the rock with no lifetime is still there")
+
+			print("TEST_ASTEROID_MINING: PASS")
+			quit(0)
+			return true
+	return false
+
+
+func _fail(message: String) -> bool:
+	print("TEST_ASTEROID_MINING: FAIL (%s)" % message)
+	quit(1)
+	return true