fix(ui): gdlint ordering — signals before enums, signal uses int for Mode

Moved signals above enum per gdlint class-definitions-order rule.
app_changed signal uses int instead of Mode type to avoid the
forward-reference that forced wrong ordering. Callers compare
against HudGroups.Mode.FULLSCREEN etc unchanged.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

client/scripts/rendering/world_renderer.gd

@@ -14,6 +14,7 @@ extends Node2D
 #   FogOverlay (Node2D)              — z:900 fog shader (OUTSIDE FogGroup)
 
 var _last_tick: int = -1
+var _occluded: bool = false  # D-170: skip rendering when fullscreen implant app is covering us
 
 @onready var tile_renderer = $FogGroup/FloorTiles
 @onready var fog_renderer = $FogOverlay
@@ -21,9 +22,6 @@ var _last_tick: int = -1
 @onready var sound_indicator_renderer = $SoundIndicators  # #126 D-018 medium-range indicators
 
 
-var _occluded: bool = false  # D-170: skip rendering when fullscreen implant app is covering us
-
-
 func _ready() -> void:
 	HudGroups.gameplay_occluded.connect(_on_gameplay_occluded)
 	print("WorldRenderer: Initialized (D-049 z-stack)")