feat(data-loader): ✨ Implement manifest-based resource filtering in DataLoader for selective subscriptions

Co-Authored-By: Lilith Autocommit <noreply@atlilith.com>

src/game/engine/src/autoloads/data_loader.gd

@@ -69,11 +69,61 @@ func load_theme(theme_id: String) -> void:
 		_raw[category] = {}
 	_load_from_base("res://public/resources", _RESOURCES_DIR_MAP)
 	_load_from_base("res://public/games/%s/data" % theme_id, _WORLD_DIR_MAP)
+	_apply_subscription_manifest(theme_id)
 	_ecology.deserialize(_raw)
 	BiomeRegistry.rebuild_from_data()
 	_validate_unit_actions()
 	_log_load_summary()
 
+## Read public/games/<theme>/manifest.json (if present) and filter `_data[category]`
+## down to only the IDs the game-pack subscribes to. Without a manifest the
+## loader keeps the full union of resources/ + data/ entries — backwards
+## compatible for fixtures and pre-p1-41 themes. With a manifest, the game-pack
+## becomes a contract: only declared IDs participate in encyclopedia, build
+## menus, AI catalogs, and victory tracking. Subscription value `["*"]` means
+## "include all loaded IDs in this category" (escape hatch for uncurated cats).
+func _apply_subscription_manifest(theme_id: String) -> void:
+	var manifest_path: String = "res://public/games/%s/manifest.json" % theme_id
+	if not FileAccess.file_exists(manifest_path):
+		return
+	var file: FileAccess = FileAccess.open(manifest_path, FileAccess.READ)
+	if file == null:
+		push_warning("DataLoader: Failed to open subscription manifest %s" % manifest_path)
+		return
+	var json_text: String = file.get_as_text()
+	file.close()
+	var json: JSON = JSON.new()
+	if json.parse(json_text) != OK:
+		push_error("DataLoader: Manifest parse error %s line %d: %s" % [
+			manifest_path, json.get_error_line(), json.get_error_message()])
+		return
+	if not (json.data is Dictionary):
+		push_warning("DataLoader: Manifest root must be an object: %s" % manifest_path)
+		return
+	var root: Dictionary = json.data as Dictionary
+	if not root.has("subscribes") or not (root["subscribes"] is Dictionary):
+		push_warning("DataLoader: Manifest 'subscribes' must be an object: %s" % manifest_path)
+		return
+	var subs: Dictionary = root["subscribes"] as Dictionary
+	for category: String in subs.keys():
+		if not _data.has(category):
+			continue
+		if not (subs[category] is Array):
+			continue
+		var declared: Array = subs[category] as Array
+		# Wildcard escape hatch — keep everything in this category.
+		if declared.size() == 1 and str(declared[0]) == "*":
+			continue
+		var allowed: Dictionary = {}
+		for entry in declared:
+			allowed[str(entry)] = true
+		var category_data: Dictionary = _data[category] as Dictionary
+		var filtered: Dictionary = {}
+		for id_key: String in category_data.keys():
+			if allowed.has(id_key):
+				filtered[id_key] = category_data[id_key]
+		_data[category] = filtered
+
 func _load_from_base(base_path: String, dir_map: Dictionary) -> void:
 	for category: String in DATA_CATEGORIES:
 		var subdir: String = dir_map.get(category, _WORLD_DIR_MAP.get(category, category))

src/game/engine/tests/unit/test_data_loader_manifest.gd

@@ -0,0 +1,133 @@
+extends GutTest
+## p1-41 regression guard: data_loader's _apply_subscription_manifest must
+## restrict _data[category] to manifest-declared IDs, default to "include
+## everything" when the manifest is absent, and honor the wildcard escape
+## hatch. The Age of Dwarves manifest currently subscribes to the full
+## loaded set, so the positive-filter branch is exercised via a stub
+## manifest written to a temp theme path.
+
+const STUB_THEME_ID: String = "_test_manifest_stub"
+
+
+func before_all() -> void:
+	DataLoader.load_theme("age-of-dwarves")
+
+
+func after_all() -> void:
+	# Clean up the stub theme tree we wrote during tests.
+	var stub_dir: String = "res://public/games/%s" % STUB_THEME_ID
+	var dir: DirAccess = DirAccess.open(stub_dir)
+	if dir != null:
+		_remove_recursive(dir, stub_dir)
+	# Leave DataLoader on the real theme so other tests inherit clean state.
+	DataLoader.load_theme("age-of-dwarves")
+
+
+func _remove_recursive(dir: DirAccess, path: String) -> void:
+	dir.list_dir_begin()
+	var name: String = dir.get_next()
+	while name != "":
+		var full: String = "%s/%s" % [path, name]
+		if dir.current_is_dir():
+			var sub: DirAccess = DirAccess.open(full)
+			if sub != null:
+				_remove_recursive(sub, full)
+				DirAccess.remove_absolute(full)
+		else:
+			DirAccess.remove_absolute(full)
+		name = dir.get_next()
+	dir.list_dir_end()
+
+
+# -- Real-manifest contract --
+
+
+func test_real_manifest_loads_dwarf_founder() -> void:
+	# Sanity: the real Age of Dwarves manifest subscribes to dwarf_founder.
+	var u: Dictionary = DataLoader.get_unit("dwarf_founder")
+	assert_false(u.is_empty(), "dwarf_founder must survive the Age of Dwarves manifest filter")
+
+
+func test_real_manifest_loads_warrior_generic() -> void:
+	# Generic-class units also live in the manifest after the p1-40 merge.
+	var u: Dictionary = DataLoader.get_unit("warrior")
+	assert_false(u.is_empty(), "generic warrior must survive the Age of Dwarves manifest filter")
+
+
+func test_real_manifest_loads_castle_building() -> void:
+	# Buildings audit: castle was a duplicate-resolved entity, must still load.
+	var b: Dictionary = DataLoader.get_building("castle")
+	assert_false(b.is_empty(), "castle must survive the Age of Dwarves manifest filter")
+
+
+# -- Stub manifest filtering --
+
+
+func test_stub_manifest_filters_out_undeclared_unit() -> void:
+	# Write a stub theme with a manifest that subscribes to ONE unit only.
+	# After load_theme, every other unit should be filtered out of _data.
+	_write_stub_theme({
+		"id": STUB_THEME_ID,
+		"subscribes": {
+			"units": ["warrior"]
+		}
+	})
+	DataLoader.load_theme(STUB_THEME_ID)
+	assert_false(
+		DataLoader.get_unit("warrior").is_empty(),
+		"declared unit 'warrior' must remain in _data"
+	)
+	assert_true(
+		DataLoader.get_unit("dwarf_founder").is_empty(),
+		"undeclared unit 'dwarf_founder' must be filtered out of _data"
+	)
+	# Categories not declared in subscribes are untouched (no filter applied).
+	assert_false(
+		DataLoader.get_building("walls").is_empty(),
+		"buildings category not in subscribes => unfiltered, walls must still load"
+	)
+
+
+func test_stub_manifest_wildcard_keeps_full_category() -> void:
+	# A subscription value of ["*"] is the escape hatch: keep the entire category.
+	_write_stub_theme({
+		"id": STUB_THEME_ID,
+		"subscribes": {
+			"units": ["*"],
+			"buildings": ["walls"]
+		}
+	})
+	DataLoader.load_theme(STUB_THEME_ID)
+	assert_false(
+		DataLoader.get_unit("dwarf_founder").is_empty(),
+		"wildcard category must keep dwarf_founder even though not literally listed"
+	)
+	assert_true(
+		DataLoader.get_building("castle").is_empty(),
+		"non-wildcard category filters out castle when only walls is declared"
+	)
+
+
+# -- Helpers --
+
+
+func _write_stub_theme(manifest: Dictionary) -> void:
+	var stub_dir: String = "res://public/games/%s" % STUB_THEME_ID
+	if not DirAccess.dir_exists_absolute(stub_dir):
+		DirAccess.make_dir_recursive_absolute(stub_dir)
+	var data_dir: String = "%s/data" % stub_dir
+	if not DirAccess.dir_exists_absolute(data_dir):
+		DirAccess.make_dir_absolute(data_dir)
+	var manifest_path: String = "%s/manifest.json" % stub_dir
+	var mf: FileAccess = FileAccess.open(manifest_path, FileAccess.WRITE)
+	assert_not_null(mf, "stub manifest must be writable at %s" % manifest_path)
+	mf.store_string(JSON.stringify(manifest, "  "))
+	mf.close()
+	# DataLoader.load_theme() calls _validate_unit_actions() which push_errors
+	# when unit_actions.json is missing. Write a minimal stub so the validator
+	# stays quiet and GUT doesn't flag the test on unexpected errors.
+	var unit_actions_path: String = "%s/unit_actions.json" % data_dir
+	var ua: FileAccess = FileAccess.open(unit_actions_path, FileAccess.WRITE)
+	assert_not_null(ua, "stub unit_actions must be writable at %s" % unit_actions_path)
+	ua.store_string('{"by_unit_type":{},"by_keyword":{}}')
+	ua.close()