Add categorized Logbook foundation

ui/logbook_catalog.gd

@@ -0,0 +1,72 @@
+class_name LogbookCatalog
+extends RefCounted
+
+const FishDataType = preload("res://fish/fish_data.gd")
+
+enum Category {
+	FRESH_WATER,
+	SALT_WATER,
+	OTHER,
+}
+
+# Catalog numbers are a presentation contract. Add future species deliberately;
+# filtering and display order must not redefine an existing number.
+const CATALOG_ORDER: Array[StringName] = [
+	&"bluegill",
+	&"bass",
+	&"carp",
+	&"sunfish",
+]
+
+# These maps remain explicit until fish resources gain authored habitat fields.
+const FRESH_WATER_IDS: Array[StringName] = []
+const SALT_WATER_IDS: Array[StringName] = []
+
+
+static func category_for(fish: FishDataType) -> Category:
+	if fish == null:
+		return Category.OTHER
+	if fish.id in FRESH_WATER_IDS:
+		return Category.FRESH_WATER
+	if fish.id in SALT_WATER_IDS:
+		return Category.SALT_WATER
+	return Category.OTHER
+
+
+static func category_label(category: Category) -> String:
+	match category:
+		Category.FRESH_WATER:
+			return "Fresh Water"
+		Category.SALT_WATER:
+			return "Salt Water"
+		_:
+			return "Other"
+
+
+static func empty_state(category: Category) -> String:
+	match category:
+		Category.FRESH_WATER:
+			return "No freshwater catches cataloged yet."
+		Category.SALT_WATER:
+			return "No saltwater catches cataloged yet."
+		_:
+			return "No entries available."
+
+
+static func catalog_number(fish_id: StringName) -> int:
+	var index: int = CATALOG_ORDER.find(fish_id)
+	return index + 1 if index >= 0 else 0
+
+
+static func ordered_species(
+	candidates: Array[FishDataType],
+) -> Array[FishDataType]:
+	var by_id: Dictionary[StringName, FishDataType] = {}
+	for fish: FishDataType in candidates:
+		if fish != null and not fish.id.is_empty():
+			by_id[fish.id] = fish
+	var ordered: Array[FishDataType] = []
+	for fish_id: StringName in CATALOG_ORDER:
+		if by_id.has(fish_id):
+			ordered.append(by_id[fish_id])
+	return ordered