feat(rendering): GameplayRenderer base class — occlusion for all renderers (D-170)

New GameplayRenderer extends Node2D with built-in occlusion support.
Subclasses override _gameplay_process() and _gameplay_draw() instead
of _process() and _draw() — these are skipped when a fullscreen
implant app covers gameplay.

Migrated all 5 gameplay renderers:
- CursorRenderer: hover detection + bracket drawing paused
- EntityRenderer: position lerping paused
- FogEntities: fog dot rendering paused
- SoundIndicatorRenderer: directional arrows paused
- WorldRenderer: tile/fog/entity updates paused

No more manual occlusion wiring — the base class handles everything.

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

client/scripts/rendering/cursor_renderer.gd

@@ -1,5 +1,5 @@
 class_name CursorRenderer
-extends Node2D
+extends GameplayRenderer
 
 ## Cursor state machine — 4 geometric states, 150ms linear transitions (D-056).
 ## Insert-styled cursor on z-layer 7 (UILayer CanvasLayer).
@@ -54,7 +54,7 @@ var _bracket_a: float = 0.0
 var _alpha: float = 0.45
 
 
-func _ready() -> void:
+func _renderer_ready() -> void:
 	Input.set_mouse_mode(Input.MOUSE_MODE_HIDDEN)
 	z_index = 100  # D-170: cursor must always render above all HUD/implant layers
 	_from = _snapshot()
@@ -69,7 +69,7 @@ func _notification(what: int) -> void:
 		visible = true
 
 
-func _process(delta: float) -> void:
+func _gameplay_process(delta: float) -> void:
 	if not _mouse_inside:
 		return
 	_time += delta
@@ -243,8 +243,8 @@ func _interpolate() -> void:
 # --- Drawing ---
 
 
-func _draw() -> void:
-	# _hover_offset is computed in _detect_hover() during _process(), not recalculated
+func _gameplay_draw() -> void:
+	# _hover_offset is computed in _detect_hover() during _gameplay_process(), not recalculated
 	# here. This is safe because Camera2D (tree sibling, earlier in scene order) applies
 	# its smoothing transform before CursorRenderer._process() reads canvas_transform.
 	# Nothing modifies the canvas transform between _process() and _draw().

client/scripts/rendering/entity_renderer.gd

@@ -1,5 +1,5 @@
 class_name EntityRenderer
-extends Node2D
+extends GameplayRenderer
 
 # Entity renderer — manages entity sprites under the Entities node
 # Creates/updates/removes Sprite2D children based on entity data
@@ -35,11 +35,11 @@ var _entity_tweens: Dictionary = {}  # #521: entity_id -> {from: Color, target:
 var _entity_facing: Dictionary = {}  # #540: entity_id -> String ("north"/"east"/"south"/"west")
 
 
-func _ready() -> void:
+func _renderer_ready() -> void:
 	print("EntityRenderer: Initialized")
 
 
-func _process(delta: float) -> void:
+func _gameplay_process(delta: float) -> void:
 	# Lerp all entity visual positions toward their targets each frame.
 	# Uses framerate-independent exponential smoothing.
 	var weight := 1.0 - exp(-LERP_SPEED * delta)

client/scripts/rendering/fog_entities.gd

@@ -1,5 +1,5 @@
 class_name FogEntities
-extends Node2D
+extends GameplayRenderer
 
 ## Fog entity visualization — renders entities undergoing cognitive delay recognition
 ## in the fog layer. Between FogOverlay (z:900) and InsertOverlay (CanvasLayer 10).
@@ -50,7 +50,7 @@ var _pings: Array = []  # [{pos: Vector2, elapsed: float}]
 var _time: float = 0.0
 
 
-func _process(delta: float) -> void:
+func _gameplay_process(delta: float) -> void:
 	# Early return when idle — skip queue_redraw() when nothing to draw
 	if _entities.is_empty() and _pings.is_empty():
 		return
@@ -118,7 +118,7 @@ func update_from_state() -> void:
 		_entities.erase(eid)
 
 
-func _draw() -> void:
+func _gameplay_draw() -> void:
 	# Breathing pulse — shared across all entities
 	var pulse_t := fmod(_time, PULSE_PERIOD) / PULSE_PERIOD
 	var pulse_alpha := lerpf(PULSE_MIN_ALPHA, PULSE_MAX_ALPHA, 0.5 + 0.5 * sin(pulse_t * TAU))

client/scripts/rendering/gameplay_renderer.gd

@@ -0,0 +1,53 @@
+class_name GameplayRenderer
+extends Node2D
+## Base class for renderers that should pause when a fullscreen implant app
+## covers the gameplay view (D-170).
+##
+## Subclasses override _gameplay_process(delta) and _gameplay_draw() instead
+## of _process() and _draw(). These are only called when gameplay is visible.
+##
+## Usage:
+##   extends GameplayRenderer
+##   func _gameplay_process(delta: float) -> void: ...
+##   func _gameplay_draw() -> void: ...
+
+var gameplay_occluded: bool = false
+
+
+func _ready() -> void:
+	HudGroups.gameplay_occluded.connect(_on_gameplay_occluded)
+	_renderer_ready()
+
+
+## Override this instead of _ready() in subclasses.
+func _renderer_ready() -> void:
+	pass
+
+
+func _on_gameplay_occluded(occluded: bool) -> void:
+	gameplay_occluded = occluded
+	if occluded:
+		# Force a blank redraw so stale frames don't linger
+		queue_redraw()
+
+
+func _process(delta: float) -> void:
+	if gameplay_occluded:
+		return
+	_gameplay_process(delta)
+
+
+func _draw() -> void:
+	if gameplay_occluded:
+		return
+	_gameplay_draw()
+
+
+## Override in subclasses — called every frame when gameplay is visible.
+func _gameplay_process(_delta: float) -> void:
+	pass
+
+
+## Override in subclasses — called for draw when gameplay is visible.
+func _gameplay_draw() -> void:
+	pass

client/scripts/rendering/sound_indicator_renderer.gd

@@ -1,5 +1,5 @@
 class_name SoundIndicatorRenderer
-extends Node2D
+extends GameplayRenderer
 
 ## Medium-range sound indicators (#126, D-018).
 ## Renders directional arrows at the fog boundary for sounds outside LOS.
@@ -35,7 +35,7 @@ const COLOR_DANGER: Color = Constants.ENTITY_COLOR_HOSTILE  # Alert / threat / g
 var _indicators: Array = []
 
 
-func _process(delta: float) -> void:
+func _gameplay_process(delta: float) -> void:
 	if _indicators.is_empty():
 		return
 
@@ -84,7 +84,7 @@ func update_sound_events(events: Array) -> void:
 		queue_redraw()
 
 
-func _draw() -> void:
+func _gameplay_draw() -> void:
 	if _indicators.is_empty():
 		return
 

client/scripts/rendering/world_renderer.gd

@@ -1,4 +1,4 @@
-extends Node2D
+extends GameplayRenderer
 
 # World renderer — manages all visual representation from GameState
 # Attached to the World node in main.tscn
@@ -14,7 +14,6 @@ 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
@@ -22,19 +21,14 @@ var _occluded: bool = false  # D-170: skip rendering when fullscreen implant app
 @onready var sound_indicator_renderer = $SoundIndicators  # #126 D-018 medium-range indicators
 
 
-func _ready() -> void:
-	HudGroups.gameplay_occluded.connect(_on_gameplay_occluded)
+func _renderer_ready() -> void:
 	print("WorldRenderer: Initialized (D-049 z-stack)")
 
 
-func _on_gameplay_occluded(occluded: bool) -> void:
-	_occluded = occluded
-
-
 # Called each frame to update visuals from game state.
 # Uses tick-based invalidation — re-renders all layers when a new snapshot arrives.
 func update_from_state() -> void:
-	if _occluded:
+	if gameplay_occluded:
 		return  # D-170: skip rendering while fullscreen implant app is active
 	var tick := GameState.current_tick
 	if tick == _last_tick: