Arena polish: in-run HUD, no free loot, retire-with-winnings

- HUD arena status (top center): live wave number and run gold,
  driven by GameState signals, torn down cleanly on HUD.reset()
- Free floor weapons removed: the initial sword/shield spawn is gone
  and manually placed level.tscn weapons are deleted server-side at
  init. Gear now only enters play via the armory or enemy drops.
- Retire to Camp: new escape-menu button (shown only while alive in
  an active run) banks 100% of run gold and keeps all gear - the
  counterweight to death's 10% settlement. Exit Game and window close
  also bank winnings before quitting.
- CLAUDE.md rewritten for the gladiator arena era: core loop,
  autoloads, economy API, RPC patterns, verification workflow.

level/ui/scripts/hud_manager.gd

@@ -11,6 +11,9 @@ var tab_hint: Control = null
 var keybind_hint: Control = null
 var escape_menu: Control = null
 var run_results: Control = null
+var arena_status: Control = null
+var _wave_label: Label = null
+var _gold_label: Label = null
 
 # Player reference
 var local_player: Character = null
@@ -81,6 +84,7 @@ func _create_ui_components():
 	_create_tab_hint()
 	_create_keybind_hint()
 	_create_escape_menu()
+	_create_arena_status()
 
 ## Create action bar at bottom of screen
 func _create_action_bar():
@@ -150,6 +154,57 @@ func _create_escape_menu():
 	else:
 		push_error("[HUD] Failed to load escape_menu.tscn")
 
+## Create the arena status readout (wave + run gold, top center)
+func _create_arena_status():
+	arena_status = PanelContainer.new()
+	arena_status.name = "ArenaStatus"
+	arena_status.set_anchors_preset(Control.PRESET_CENTER_TOP)
+	arena_status.offset_top = 10
+	arena_status.grow_horizontal = Control.GROW_DIRECTION_BOTH
+	add_child(arena_status)
+
+	var margin = MarginContainer.new()
+	margin.add_theme_constant_override("margin_left", 18)
+	margin.add_theme_constant_override("margin_right", 18)
+	margin.add_theme_constant_override("margin_top", 6)
+	margin.add_theme_constant_override("margin_bottom", 6)
+	arena_status.add_child(margin)
+
+	var hbox = HBoxContainer.new()
+	hbox.add_theme_constant_override("separation", 24)
+	margin.add_child(hbox)
+
+	_wave_label = Label.new()
+	_wave_label.add_theme_font_size_override("font_size", 22)
+	_wave_label.add_theme_color_override("font_color", Color(1.0, 0.8, 0.0))
+	_wave_label.add_theme_color_override("font_outline_color", Color.BLACK)
+	_wave_label.add_theme_constant_override("outline_size", 2)
+	hbox.add_child(_wave_label)
+
+	_gold_label = Label.new()
+	_gold_label.add_theme_font_size_override("font_size", 22)
+	_gold_label.add_theme_color_override("font_color", Color(1.0, 0.85, 0.2))
+	_gold_label.add_theme_color_override("font_outline_color", Color.BLACK)
+	_gold_label.add_theme_constant_override("outline_size", 2)
+	hbox.add_child(_gold_label)
+
+	# Live updates from the economy
+	GameState.wave_changed.connect(_on_wave_changed)
+	GameState.run_gold_changed.connect(_on_run_gold_changed)
+
+	# Seed with current values (run may already be underway)
+	_on_wave_changed(GameState.current_wave)
+	_on_run_gold_changed(GameState.run_gold)
+	print("[HUD] Arena status created")
+
+func _on_wave_changed(wave: int):
+	if _wave_label:
+		_wave_label.text = "Wave %d" % wave if wave > 0 else "Prepare..."
+
+func _on_run_gold_changed(gold: int):
+	if _gold_label:
+		_gold_label.text = "Gold +%d" % gold
+
 ## Show all UI components
 func show_hud():
 	show()
@@ -165,6 +220,13 @@ func reset():
 		_disconnect_player_signals()
 	local_player = null
 
+	# Drop GameState connections so they don't fire on freed labels
+	# (and don't double-connect when the next run creates a new status bar)
+	if GameState.wave_changed.is_connected(_on_wave_changed):
+		GameState.wave_changed.disconnect(_on_wave_changed)
+	if GameState.run_gold_changed.is_connected(_on_run_gold_changed):
+		GameState.run_gold_changed.disconnect(_on_run_gold_changed)
+
 	for child in get_children():
 		child.queue_free()
 
@@ -176,6 +238,9 @@ func reset():
 	keybind_hint = null
 	escape_menu = null
 	run_results = null
+	arena_status = null
+	_wave_label = null
+	_gold_label = null
 	print("[HUD] Reset - all UI components removed")
 
 ## Player signal callbacks