Add the planet setup map editor (#48)

PlanetSetupEditor authors PlanetSetup resources: pick a surface
profile (drives the real lunar_surface background, not a blank
sheet), place/move/delete capture points and enemies from a palette
generated straight off EnemyDefinitions.all() (a new enemy definition
shows up with no editor change), pan/pinch-zoom the canvas with the
same touch idiom as GameController, then save to
res://PlanetSetups/<id>.tres via ResourceSaver - reachable now from
the main menu's Map Editor button. The mutation methods
(new_setup/load_setup/add_*/move_*/remove_*/save_setup) are the whole
model and work standalone, which is what lets
tests/test_setup_editor.gd drive placement/move/delete/save/reload
directly without simulating touch input.

Every cross-file reference is a preloaded script const rather than a
bare global class name, matching #42/#44's load-order notes - this
file is instantiated from other scripts' function bodies, never as a
script-mode test entry point itself, so it wasn't at risk the same way
the test files were, but the pattern is kept consistent throughout.

Part of the #40 conquest-mechanic breakdown. This closes out the
breakdown: #41-#48 are now all implemented, tested, and merged.

tests/test_setup_editor.gd

@@ -0,0 +1,136 @@
+extends SceneTree
+
+# Headless gameplay test: run with
+#   godot --headless -s res://tests/test_setup_editor.gd
+# Drives PlanetSetupEditor's model directly (place/move/delete/save/reload)
+# rather than through touch input - see the ticket's own note that the
+# touch layer can stay out of the headless test. Verifies:
+#   1. placing capture points and enemies updates current_setup
+#   2. moving and deleting update it correctly, including index shifting
+#   3. saving writes a real res://PlanetSetups/<id>.tres and the registry
+#      picks it up
+#   4. reopening that file in a fresh editor instance round-trips the
+#      exact points/enemies, and they can be moved/deleted again
+#   5. the palette has one entry per EnemyDefinitions entry plus the
+#      capture point, generated from the registry rather than hardcoded
+
+const TEST_SETUP_ID: String = "test_editor_setup"
+const TEST_SETUP_PATH: String = "res://PlanetSetups/test_editor_setup.tres"
+
+var editor: Node
+var stage: int = 0
+var elapsed: float = 0.0
+
+
+func _initialize() -> void:
+	_cleanup_scratch_file()
+	editor = load("res://PlanetSetupEditor.tscn").instantiate()
+	root.add_child(editor)
+
+
+func _process(delta: float) -> bool:
+	elapsed += delta
+	match stage:
+		0:
+			# _ready() (palette build, initial new_setup) needs a frame to
+			# flush - same hazard as test_planet_setups.gd.
+			if elapsed < 0.1:
+				return false
+
+			var expected_palette_size: int = 1 + EnemyDefinitions.all().size()
+			if editor._palette_buttons.size() != expected_palette_size:
+				return _fail("palette has %d entries, expected 1 + %d enemy definitions" % [
+					editor._palette_buttons.size(), EnemyDefinitions.all().size()
+				])
+
+			editor.new_setup(TEST_SETUP_ID, "Test Editor Setup", "rocky")
+			editor.add_capture_point(Vector2(100, 200))
+			editor.add_capture_point(Vector2(-300, 50))
+			editor.add_capture_point(Vector2(0, -400))
+			editor.add_enemy("chaser", Vector2(500, 500))
+			editor.add_enemy("sniper", Vector2(-500, -500))
+
+			if editor.current_setup.capture_points.size() != 3:
+				return _fail("placing 3 capture points did not land 3")
+			if editor.current_setup.enemy_spawns.size() != 2:
+				return _fail("placing 2 enemies did not land 2")
+
+			editor.move_capture_point(0, Vector2(150, 250))
+			if editor.current_setup.capture_points[0] != Vector2(150, 250):
+				return _fail("move_capture_point did not update the position")
+
+			editor.remove_enemy(0)   # removes the chaser spawn
+			if editor.current_setup.enemy_spawns.size() != 1:
+				return _fail("remove_enemy did not shrink enemy_spawns")
+			if editor.current_setup.enemy_spawns[0].enemy_id != "sniper":
+				return _fail("remove_enemy removed the wrong entry (index did not shift)")
+
+			var result: Dictionary = editor.save_setup()
+			if not result.ok:
+				return _fail("save_setup reported failure: %s" % result.message)
+			if not FileAccess.file_exists(TEST_SETUP_PATH):
+				return _fail("save_setup reported success but wrote no file at %s" % TEST_SETUP_PATH)
+
+			var found_in_registry: bool = false
+			for setup in PlanetSetups.all():
+				if setup.setup_id == TEST_SETUP_ID:
+					found_in_registry = true
+			if not found_in_registry:
+				return _fail("saved setup was not picked up by PlanetSetups after save")
+
+			elapsed = 0.0
+			stage = 1
+			return false
+		1:
+			if elapsed < 0.1:
+				return false
+			# Reopen in a FRESH editor instance, as a re-landing/re-editing
+			# session would.
+			var reopened: Node = load("res://PlanetSetupEditor.tscn").instantiate()
+			root.add_child(reopened)
+			editor = reopened
+			elapsed = 0.0
+			stage = 2
+			return false
+		2:
+			if elapsed < 0.1:
+				return false
+			if not editor.load_setup(TEST_SETUP_ID):
+				return _fail("reopening the saved setup failed")
+			var points: PackedVector2Array = editor.current_setup.capture_points
+			var spawns: Array = editor.current_setup.enemy_spawns
+			if points.size() != 3 or points[0] != Vector2(150, 250) \
+					or points[1] != Vector2(-300, 50) or points[2] != Vector2(0, -400):
+				return _fail("reopened capture points did not match what was saved: %s" % [points])
+			if spawns.size() != 1 or spawns[0].enemy_id != "sniper" or spawns[0].position != Vector2(-500, -500):
+				return _fail("reopened enemy spawns did not match what was saved")
+
+			# The reopened items can still be moved and deleted.
+			editor.move_enemy(0, Vector2(-600, -600))
+			if editor.current_setup.enemy_spawns[0].position != Vector2(-600, -600):
+				return _fail("could not move an item after reopening")
+			editor.remove_capture_point(1)
+			if editor.current_setup.capture_points.size() != 2:
+				return _fail("could not delete an item after reopening")
+
+			print("TEST_SETUP_EDITOR: PASS")
+			_cleanup_scratch_file()
+			quit(0)
+			return true
+	return false
+
+
+func _cleanup_scratch_file() -> void:
+	if FileAccess.file_exists(TEST_SETUP_PATH):
+		DirAccess.remove_absolute(ProjectSettings.globalize_path(TEST_SETUP_PATH))
+	var import_file: String = TEST_SETUP_PATH + ".import"
+	if FileAccess.file_exists(import_file):
+		DirAccess.remove_absolute(ProjectSettings.globalize_path(import_file))
+	PlanetSetups.rescan()
+
+
+func _fail(message: String) -> bool:
+	print("TEST_SETUP_EDITOR: FAIL (%s)" % message)
+	_cleanup_scratch_file()
+	quit(1)
+	return true