fix(client): resolve GDScript autoload parse-order errors

Autoload scripts are parsed before regular scripts, so class_name
types (CharacterVisualDescriptor, TestHarness, YamlParser) are not
available at parse time. Replace type annotations with untyped vars
and use load() for in-body class references. Fixes all 14 headless
parse errors (9 pre-existing + 5 from Sprint 30 changes).

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

client/scripts/autoloads/sim_bridge.gd

@@ -5,7 +5,8 @@ enum ConnectionState { DISCONNECTED, CONNECTING, HANDSHAKING, CONNECTED, ERROR }
 
 var state: ConnectionState = ConnectionState.DISCONNECTED
 var test_mode: bool = OS.get_environment("SR_LIVE") != "1"  # SR_LIVE=1 connects to real server
-var harness: TestHarness = null  # Test simulation (D-020: game logic lives outside production client)
+# Type is TestHarness — untyped to avoid autoload parse-order issue.
+var harness = null  # Test simulation (D-020: game logic lives outside production client)
 var _last_snapshot: Variant = null  # Most recent decoded snapshot (consumed by poll_snapshot)
 var _outbound_buffer: Array[Dictionary] = []  # Raw inputs awaiting batch encode + transport
 
@@ -33,7 +34,7 @@ signal handshake_failed(reason: String)
 
 func _ready() -> void:
 	if test_mode:
-		harness = TestHarness.new()
+		harness = load("res://scripts/protocol/test_harness.gd").new()
 		print("SimBridge: Running in test mode (dynamic snapshot)")