Show what the fleet is carrying next to what is banked

Forgejo #15, part 2 of #12. Since #14 ore is cargo until the fleet
delivers it to the mothership, so the banked readout does not move on
pickup - mining looked broken, because gathering ore changed no number
on screen until the fleet happened to fly home.

Three things separate the carried readout from the banked one, since
colour alone is a weak signal on a phone in a game that is mostly teal:
amber rather than ore-teal (the same amber already used for ore in
transit - the extractor derrick, the hauler route), smaller and sitting
under the banked figure so it reads as subordinate, and present only
while actually carrying, so an empty hold is not a permanent 0 parked
beside the real total.

Rendered via tests/screenshot.sh and looked at, not only asserted on:
headless draws no pixels and cannot say whether two numbers read as two
different things.

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

tests/test_cargo_readout.gd

@@ -0,0 +1,117 @@
+extends SceneTree
+
+# Headless gameplay test: run with
+#   godot --headless -s res://tests/test_cargo_readout.gd
+# Forgejo #15 (part 2 of #12): what the fleet is carrying has to be visible
+# separately from what is banked.
+#
+# Since #14, ore is cargo until the fleet delivers it to the mothership. The
+# banked readout does not move on pickup, so without a second readout mining
+# looks broken - you gather ore and no number on screen changes.
+#
+# --headless has no GPU and draws no pixels, so this asserts on the two
+# readouts' state, not on their appearance. tests/screenshot.sh covers
+# whether they are legible.
+#
+# Verifies:
+#   1. the banked readout keeps showing the BANK, not the total
+#   2. the cargo readout shows the hold, and appears only while carrying
+#   3. an empty hold hides it rather than parking a permanent 0 beside the
+#      real total
+#   4. delivering moves the number from one readout to the other
+#   5. the two are actually told apart on screen, rather than being the same
+#      number twice in the same colour at the same place
+
+var game_state: Node
+var scene: Node
+var banked: Control
+var cargo: Control
+var stage: int = 0
+var elapsed: float = 0.0
+
+
+func _initialize() -> void:
+	game_state = root.get_node("GameState")
+	game_state.buildings.clear()
+	game_state.extractors.clear()
+	game_state.rocks = 42
+	game_state.fleet_cargo = 0
+	scene = load("res://Main.tscn").instantiate()
+	root.add_child(scene)
+	banked = scene.get_node("UI/ResourceCounter")
+	cargo = scene.get_node("UI/CargoCounter")
+
+
+func _process(delta: float) -> bool:
+	elapsed += delta
+	match stage:
+		0:
+			if elapsed < 0.2:
+				return false
+			# --- 3. nothing carried -> no cargo readout -----------------
+			if cargo.visible:
+				print("TEST_CARGO_READOUT: FAIL (cargo readout showing with an empty hold)")
+				quit(1)
+				return true
+			if banked.amount != 42:
+				print("TEST_CARGO_READOUT: FAIL (banked readout shows %d, bank is 42)" % banked.amount)
+				quit(1)
+				return true
+			print("empty hold -> cargo readout hidden, banked shows %d" % banked.amount)
+
+			game_state.collect_cargo(7)
+			elapsed = 0.0
+			stage = 1
+			return false
+		1:
+			if elapsed < 0.2:
+				return false
+			# --- 1 + 2. carried and banked are separate numbers ---------
+			if not cargo.visible:
+				print("TEST_CARGO_READOUT: FAIL (carrying 7 and the cargo readout is hidden)")
+				quit(1)
+				return true
+			if cargo.amount != 7:
+				print("TEST_CARGO_READOUT: FAIL (cargo readout shows %d, hold is 7)" % cargo.amount)
+				quit(1)
+				return true
+			if banked.amount != 42:
+				print("TEST_CARGO_READOUT: FAIL (banked readout moved to %d on a pickup - it is showing the total, not the bank)" % banked.amount)
+				quit(1)
+				return true
+			print("carrying 7 -> cargo=%d banked=%d" % [cargo.amount, banked.amount])
+
+			# --- 5. genuinely distinguishable ---------------------------
+			if cargo.glow_color == banked.glow_color:
+				print("TEST_CARGO_READOUT: FAIL (both readouts drawn in the same colour)")
+				quit(1)
+				return true
+			if cargo.position == banked.position:
+				print("TEST_CARGO_READOUT: FAIL (both readouts in the same place)")
+				quit(1)
+				return true
+			print("distinct: colours %s vs %s, at %s vs %s" % [
+				cargo.glow_color, banked.glow_color, cargo.position, banked.position
+			])
+
+			# --- 4. delivery moves it across ----------------------------
+			game_state.deliver_cargo()
+			elapsed = 0.0
+			stage = 2
+			return false
+		2:
+			if elapsed < 0.2:
+				return false
+			if cargo.visible:
+				print("TEST_CARGO_READOUT: FAIL (cargo readout still showing after delivery)")
+				quit(1)
+				return true
+			if banked.amount != 49:
+				print("TEST_CARGO_READOUT: FAIL (banked shows %d after delivering 7 into 42)" % banked.amount)
+				quit(1)
+				return true
+			print("delivered -> cargo hidden, banked shows %d" % banked.amount)
+			print("TEST_CARGO_READOUT: PASS")
+			quit(0)
+			return true
+	return false