Restructure into core/ and content/official/

game/core/modding/modifier.gd

@@ -0,0 +1,40 @@
+extends Resource
+class_name Modifier
+# One modifier definition: title + description + texture + scoring rule.
+# Create instances of this as .tres files in the editor (right-click in
+# FileSystem -> New Resource -> Modifier), OR build them in code in the catalog.
+#
+# Because a texture always maps to the same modifier, the texture lives HERE.
+
+# A stable unique id (e.g. "stars_x5"). Useful for saving which modifiers are
+# applied to which segments, and for lookups. Keep it unique across the catalog.
+@export var id: String = ""
+
+# Shown to the player when offered the piece.
+@export var title: String = ""
+@export_multiline var description: String = ""
+
+# The texture painted onto the segment when this modifier is applied.
+@export var texture: Texture2D
+
+# --- Scoring rule ---
+# Simple, data-only rules cover most cases without writing code per modifier.
+# value = (base_value * mult + add) for the affected segment.
+@export var score_mult: float = 1.0
+@export var score_add: int = 0
+
+# Optional: rarity weight for random selection (higher = more common).
+@export var weight: float = 1.0
+
+# Apply this modifier's rule to a segment's base value.
+func apply_score(base_value: int) -> int:
+	return int(round(base_value * score_mult)) + score_add
+
+# A short human-readable summary of the effect, for tooltips/UI.
+func effect_text() -> String:
+	var parts: Array[String] = []
+	if score_mult != 1.0:
+		parts.append("x%s" % str(score_mult))
+	if score_add != 0:
+		parts.append(("+%d" % score_add) if score_add > 0 else str(score_add))
+	return " ".join(parts) if parts.size() > 0 else "no change"