Add Pac-Man power-on flow and document Odin integration

- Add a four-second arcade-style boot sequence followed by the
  Character / Nickname introduction.
- Separate cabinet power-on from RFID credit and player Start.
- Add operator Power on control and cabinet power-state reporting.
- Prevent repeated power commands from restarting boot or gameplay.
- Ignore RFID scans received before the cabinet is ready.
- Add power-state, RFID, controller, and GPIO feedback regression tests.

- Expand the master walkthrough with export, packaging, file transfer,
  fresh-Pi setup, RFID compilation, and end-to-end testing instructions.
- Correct tester hardware documentation: BCM23/J20 drives an LED;
  physical buttons connect through a separate I2C1 input board.
- Document operator-triggered power-on as the current test workflow
  and retain the temporary 2.4 configuration compatibility notes.
- Record successful physical testing of power-on, RFID credit,
  and player Start.

- Add an Odin integration README describing the proposed Rust/NATS
  bridge, shared messages, Flutter GM interface, autopilot sequencing,
  hardware ownership, and Starfish SSH-management role.
- Define migration milestones and information needed from the
  framework owner; link the integration guide from the root README.

Validation: 69 controller tests, 10 GPIO tests, Pac-Man power/RFID
checks, managed-cabinet lifecycle checks, and visual screen inspection.

core/network/managed_cabinet.gd

@@ -1,5 +1,5 @@
 extends Node
-const VERSION := "arcade-cabinet-2.3"
+const VERSION := "arcade-cabinet-2.4"
 var cabinet_id := "cabinet_01"
 var database: ProjectDatabase = preload("res://data/project_database.tres")
 var cabinet: CabinetProfile
@@ -55,12 +55,12 @@ func _ready() -> void:
 func poll() -> void:
 	if busy or executing: return
 	busy = true
-	if game != null and phase == "ready" and game.has_method("receive_device_feedback") and HardwareManager.real_gpio and HardwareManager.client != null:
+	if game != null and phase in ["ready", "powered_off", "booting"] and game.has_method("receive_device_feedback") and HardwareManager.real_gpio and HardwareManager.client != null:
 		game.receive_device_feedback(HardwareManager.client.get_feedback())
 	var sent := reports.duplicate(true)
 	var result: Dictionary = await connection.post("/cabinet/poll", {
 		"cabinet": cabinet_id, "protocol": 2, "boot": boot, "version": VERSION,
-		"features": ["assignment_config_v1", "device_feedback_v1", "rfid_credit_v1"],
+		"features": ["assignment_config_v1", "device_feedback_v1", "rfid_credit_v1", "pacman_power_v1"],
 		"feedback": HardwareManager.client.get_feedback() if HardwareManager.real_gpio and HardwareManager.client != null else {},
 		"gpio": "real" if HardwareManager.real_gpio else "simulation", "reports": sent,
 	})
@@ -127,14 +127,19 @@ func execute(command: Dictionary) -> void:
 			if str(definition.game_id) == "missile_command": game.set("relative_mouse_aim", true)
 			Input.mouse_mode = Input.MOUSE_MODE_CAPTURED if str(definition.game_id) in ["missile_command", "tempest"] else Input.MOUSE_MODE_VISIBLE
 			add_child(game)
+			if game.has_signal("power_state_changed"):
+				game.power_state_changed.connect(_power_changed)
 			game.configure(command.get("game_config", {}).duplicate(true))
 			if game.has_method("receive_device_feedback") and HardwareManager.client != null:
 				game.receive_device_feedback(HardwareManager.client.get_feedback())
 			game.game_started.connect(func(): event("started"))
 			game.game_won.connect(func(): event("won"))
 			game.game_lost.connect(func(): event("lost"))
-			phase = "ready"
-			acknowledge(command, true, definition.display_name + " loaded and ready")
+			phase = {"off": "powered_off", "booting": "booting", "ready": "ready"}.get(str(game.get("power_state")), "ready") if game.has_signal("power_state_changed") else "ready"
+			acknowledge(command, true, definition.display_name + " loaded: " + phase)
+		"power_on":
+			var ok: bool = game != null and phase == "powered_off" and game.has_method("power_on") and game.power_on()
+			acknowledge(command, ok, "Power-on requested" if ok else "Cabinet is not powered off")
 		"start":
 			var ok: bool = game != null and phase == "ready" and game.start_game()
 			acknowledge(command, ok, "Game started" if ok else "Cabinet was not ready")
@@ -158,3 +163,8 @@ func execute(command: Dictionary) -> void:
 			acknowledge(command, ok, "GPIO bridge accepted pulse; delivery unconfirmed" if ok else "GPIO failed or acknowledgement lost; inspect cabinet")
 		_:
 			acknowledge(command, false, "Unsupported command")
+
+func _power_changed(state: String) -> void:
+	if state == "off": return # prepare acknowledgement establishes this state
+	phase = "booting" if state == "booting" else "ready"
+	event("power_booting" if state == "booting" else "power_ready")