feat(client): initialize Godot 4 project boilerplate (epic #277)

Set up the complete Godot 4.6 client foundation as a pure renderer (D-020):
- project.godot with 2D rendering, autoloads, input actions
- Main scene: Game > World (TileMapLayer, Entities, FogOverlay) + Camera2D + UILayer
- Autoloads: SimBridge (connection state machine + test mode), GameState, InputMapper
- Rendering stubs: WorldRenderer, EntityRenderer, FogRenderer
- UI stubs: HUD (health/perception/time), Minimap, MonologueDisplay
- Input mapping: WASD/arrows, E (interact), Tab (perception), Esc (menu), Space (pause)
- gdUnit4 smoke tests: scene loads, autoloads registered (2/2 passing)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

client/scripts/rendering/entity_renderer.gd

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+extends Node2D
+
+# Entity renderer — manages entity sprites under the Entities node
+# Creates/updates/removes Sprite2D children based on entity data
+
+var entity_nodes: Dictionary = {}  # id -> Node2D mapping
+
+func _ready() -> void:
+	print("EntityRenderer: Initialized")
+
+# Update entities from snapshot data
+func update_entities(entities: Array) -> void:
+	var active_ids: Array = []
+
+	# Create or update entities
+	for entity_data in entities:
+		if not entity_data.has("id"):
+			continue
+
+		var entity_id = entity_data.id
+		active_ids.append(entity_id)
+
+		# Create entity node if it doesn't exist
+		if not entity_nodes.has(entity_id):
+			_create_entity_node(entity_id, entity_data)
+		else:
+			_update_entity_node(entity_id, entity_data)
+
+	# Remove entities that are no longer visible
+	var ids_to_remove: Array = []
+	for entity_id in entity_nodes.keys():
+		if entity_id not in active_ids:
+			ids_to_remove.append(entity_id)
+
+	for entity_id in ids_to_remove:
+		_remove_entity_node(entity_id)
+
+# Create a new entity node (placeholder visual)
+func _create_entity_node(entity_id: int, entity_data: Dictionary) -> void:
+	var entity_node = ColorRect.new()
+	entity_node.name = "Entity_" + str(entity_id)
+	entity_node.size = Vector2(32, 32)
+	entity_node.pivot_offset = Vector2(16, 16)
+
+	# Color based on type
+	if entity_data.get("type") == "npc":
+		entity_node.color = Color(0.3, 0.6, 0.9)  # Blue for NPCs
+	else:
+		entity_node.color = Color(0.8, 0.8, 0.8)  # Gray for unknown
+
+	add_child(entity_node)
+	entity_nodes[entity_id] = entity_node
+
+	_update_entity_node(entity_id, entity_data)
+
+# Update an existing entity node
+func _update_entity_node(entity_id: int, entity_data: Dictionary) -> void:
+	if not entity_nodes.has(entity_id):
+		return
+
+	var entity_node = entity_nodes[entity_id]
+
+	# Update position
+	if entity_data.has("position"):
+		var pos = entity_data.position
+		entity_node.position = Vector2(pos[0] * 32, pos[1] * 32)  # 32px grid
+
+# Remove an entity node
+func _remove_entity_node(entity_id: int) -> void:
+	if not entity_nodes.has(entity_id):
+		return
+
+	var entity_node = entity_nodes[entity_id]
+	entity_node.queue_free()
+	entity_nodes.erase(entity_id)

client/scripts/rendering/entity_renderer.gd.uid

@@ -0,0 +1 @@
+uid://civev5c8xvtc3

client/scripts/rendering/fog_renderer.gd

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+extends Node2D
+
+# Fog renderer — manages fog of war overlay
+# Controls visibility based on player position and fog radius
+
+func _ready() -> void:
+	print("FogRenderer: Initialized")
+
+# Update fog visibility (stub for now)
+func update_fog(fog_data: Dictionary, player_pos: Vector2) -> void:
+	# TODO: Implement fog of war rendering
+	# This will control what the player can see based on:
+	# - fog_data.radius (visibility radius)
+	# - player_pos (center of visible area)
+	# - Perception mode state (affects visibility)
+	pass

client/scripts/rendering/fog_renderer.gd.uid

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+uid://cfyv4qt7yybib

client/scripts/rendering/world_renderer.gd

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+extends Node2D
+
+# World renderer — manages all visual representation from GameState
+# Attached to the World node in main.tscn
+
+@onready var entity_renderer = $Entities
+@onready var fog_renderer = $FogOverlay
+
+func _ready() -> void:
+	print("WorldRenderer: Initialized")
+
+# Called each frame to update visuals from game state
+func update_from_state() -> void:
+	# Update entity sprites
+	if entity_renderer and entity_renderer.has_method("update_entities"):
+		entity_renderer.update_entities(GameState.visible_entities)
+
+	# Update fog overlay
+	if fog_renderer and fog_renderer.has_method("update_fog"):
+		fog_renderer.update_fog(GameState.fog_state, GameState.player_position)

client/scripts/rendering/world_renderer.gd.uid

@@ -0,0 +1 @@
+uid://djon0gnkn6sh2