feat: adding the skin_shader_generator, and gacha base barebone

scripts/ui/profile_panel.gd

@@ -33,6 +33,7 @@ signal profile_updated
 @onready var costume_tab_btn  := %CostumeTabBtn  as Button
 @onready var glove_tab_btn    := %GloveTabBtn    as Button
 @onready var acc_tab_btn      := %AccTabBtn      as Button
+@onready var frag_tab_btn     := %FragTabBtn     as Button
 @onready var drag_zone        := %DragZone       as Control
 @onready var character_root   := %CharacterRoot  as Node3D
 @onready var char_left_btn    := %CharLeftBtn    as Button
@@ -173,6 +174,7 @@ func _connect_signals() -> void:
 	costume_tab_btn.pressed.connect(func(): _on_category_tab_pressed("costume"))
 	glove_tab_btn.pressed.connect(func():   _on_category_tab_pressed("glove"))
 	acc_tab_btn.pressed.connect(func():     _on_category_tab_pressed("accessory"))
+	frag_tab_btn.pressed.connect(func():    _on_category_tab_pressed("fragment"))
 
 	# Item grid slot buttons
 	for i in _item_slots.size():
@@ -248,13 +250,18 @@ func _highlight_active_tab() -> void:
 		"head":      head_tab_btn,
 		"costume":   costume_tab_btn,
 		"glove":     glove_tab_btn,
-		"accessory": acc_tab_btn
+		"accessory": acc_tab_btn,
+		"fragment":  frag_tab_btn
 	}
 	for cat: String in map:
 		(map[cat] as Button).modulate = Color(1.3, 1.3, 0.4, 1) if cat == _current_category else Color.WHITE
 
 func _rebuild_category_items() -> void:
 	_category_items.clear()
+	# Fragment tab handled separately
+	if _current_category == "fragment":
+		_rebuild_fragment_items()
+		return
 	var prefix       := _current_category + "_"
 	# Resolve the current character's node name (e.g. "Copper" → "Oldpop")
 	var current_char_display: String  = CHARACTERS[_loadout_index]
@@ -283,6 +290,12 @@ func _rebuild_category_items() -> void:
 # ─────────────────────────────────────────────────────────────
 # Item grid
 # ─────────────────────────────────────────────────────────────
+func _rebuild_fragment_items() -> void:
+	var frags: Dictionary = UserProfileManager.fragments
+	for fid in ["frag_common", "frag_uncommon", "frag_rare"]:
+		var count: int = frags.get(fid, 0)
+		if count > 0: _category_items.append(fid)
+
 func _populate_item_grid() -> void:
 	var start: int       = _current_page * ITEMS_PER_PAGE
 	var total: int       = _category_items.size()