fix(client): address PR review — input bug, bounds checks, fixture tests

- Fix input_mapper double-check bug (redundant InputEventKey + pressed filter)
- Add bounds checking for position arrays in entity_renderer and game_state
- Make test snapshot deterministic (incrementing counter, not wall clock)
- Fix tween overlap in monologue_display (cancel active tween before new one)
- Extract TILE_SIZE constant from magic number 32
- Add 5 D-030 Layer 1 fixture tests for snapshot parsing (7/7 total passing)

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

client/scripts/rendering/entity_renderer.gd

@@ -3,6 +3,8 @@ extends Node2D
 # Entity renderer — manages entity sprites under the Entities node
 # Creates/updates/removes Sprite2D children based on entity data
 
+const TILE_SIZE: int = 32
+
 var entity_nodes: Dictionary = {}  # id -> Node2D mapping
 
 func _ready() -> void:
@@ -63,7 +65,10 @@ func _update_entity_node(entity_id: int, entity_data: Dictionary) -> void:
 	# Update position
 	if entity_data.has("position"):
 		var pos = entity_data.position
-		entity_node.position = Vector2(pos[0] * 32, pos[1] * 32)  # 32px grid
+		if pos is Array and pos.size() >= 2:
+			entity_node.position = Vector2(pos[0] * TILE_SIZE, pos[1] * TILE_SIZE)
+		else:
+			push_warning("EntityRenderer: malformed position for entity %s" % entity_id)
 
 # Remove an entity node
 func _remove_entity_node(entity_id: int) -> void: