feat(client): hub teleport UX — Home key, fade transition (#501)

Home key sends TeleportToHub in Gauntlet mode. Camera snaps to hub
spawn with 0.3s fade-from-black. Clears dialogue/monologue buffers
on teleport. Teleport detection uses distance threshold (>5 tiles)
so future teleport types get the transition for free.

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

client/scripts/autoloads/sim_bridge.gd

@@ -269,6 +269,8 @@ static func _action_enum_to_wire(action: int) -> String:
 			return ""  # Client-only action (#495), not part of wire protocol
 		InputMapper.Action.SET_FACING:
 			return "SetFacing"  # D-054: facing octant update (no movement)
+		InputMapper.Action.TELEPORT_HUB:
+			return "TeleportToHub"  # #501: hub teleport (Gauntlet-only)
 		_:
 			push_warning("SimBridge: unknown action enum %s" % action)
 			return ""
@@ -284,6 +286,11 @@ func _test_snapshot() -> Dictionary:
 
 	# Process queued inputs
 	for action_name in _test_input_queue:
+		if action_name == "TeleportToHub":
+			# #501: Reset to hub spawn position, clear dialogue
+			_test_player_pos = Vector2i(10, 10)
+			_test_in_dialogue = false
+			continue
 		if action_name == "Interact":
 			# Mock dialogue trigger (#434): if near NPC, start dialogue
 			var npc_pos := Vector2i(12, 9)