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/world_renderer.gd

@@ -0,0 +1,20 @@
+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)