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.

games/pacman/pacman.gd

@@ -13,6 +13,10 @@ var model = Model.new()
 var view
 var audio
 var accumulator := 0.0
+signal power_state_changed(state: String)
+const BOOT_SECONDS := 4.0
+var power_state := "off"
+var boot_elapsed := 0.0
 var credits := 0
 var rfid_seen: Dictionary = {}
 var rfid_initialized := false
@@ -30,7 +34,11 @@ func receive_device_feedback(feedback: Dictionary) -> void:
 		var ident := str(entry.get("id", ""))
 		if ident.is_empty() or rfid_seen.has(ident): continue
 		rfid_seen[ident] = true
-		if device_id.is_empty() or is_running or credits > 0 or model.state != "idle": continue
+		if power_state == "off" and entry.get("device") == run_config.get("power_on_device", "") and entry.get("kind") == "input" and entry.get("value") == true and str(entry.get("error", "")).is_empty():
+			for sample in feedback.get("devices", []):
+				if sample.get("id") == entry.get("device") and int(entry.get("age_ms", 999999)) < 2000 and int(sample.get("age_ms", 999999)) < 2000 and str(sample.get("error", "")).is_empty():
+					power_on()
+		if power_state != "ready" or device_id.is_empty() or is_running or credits > 0 or model.state != "idle": continue
 		if entry.get("device") != device_id or entry.get("kind") != "rfid" or not str(entry.get("error", "")).is_empty(): continue
 		var uid := str(entry.get("value", "")).to_upper()
 		if uid.is_empty(): continue
@@ -57,13 +65,40 @@ func _ready() -> void:
 	model.sound_requested.connect(audio.play_effect)
 	model.finished.connect(_on_finished)
 	_apply_config()
+	if str(run_config.get("power_on_device", "")).is_empty(): power_on()
 
 func configure(config: Dictionary = {}) -> void:
+	power_off()
 	super.configure(config)
 	credits = 0
 	rfid_seen.clear()
 	rfid_initialized = false
 	_apply_config()
+	if str(run_config.get("power_on_device", "")).is_empty(): power_on()
+
+func power_on() -> bool:
+	if power_state != "off": return false
+	boot_elapsed = 0.0
+	power_state = "booting"
+	view.power_state = power_state
+	view.startup_time = 0.0
+	audio.stop_all()
+	power_state_changed.emit(power_state)
+	return true
+
+func power_off() -> void:
+	is_running = false
+	credits = 0
+	boot_elapsed = 0.0
+	power_state = "off"
+	model.reset()
+	accumulator = 0.0
+	if audio != null: audio.stop_all()
+	if view != null:
+		view.power_state = power_state
+		view.startup_time = 0.0
+		view.credits = 0
+	power_state_changed.emit(power_state)
 
 func _apply_config() -> void:
 	if view != null:
@@ -75,7 +110,7 @@ func _apply_config() -> void:
 	model.extra_life_score = maxi(0, int(run_config.get("extra_life_score", extra_life_score)))
 
 func start_game() -> bool:
-	if is_running: return false
+	if is_running or power_state != "ready": return false
 	if not str(run_config.get("rfid_credit_device", "")).is_empty():
 		if credits < 1: return false
 		credits -= 1
@@ -117,6 +152,19 @@ func _unhandled_input(event: InputEvent) -> void:
 		if event.is_action_pressed(pair[0]): model.requested = pair[1]
 
 func _physics_process(delta: float) -> void:
+	if power_state == "off": return
+	if power_state == "booting":
+		boot_elapsed = minf(BOOT_SECONDS, boot_elapsed + delta)
+		view.startup_time = boot_elapsed
+		if boot_elapsed >= BOOT_SECONDS:
+			power_state = "ready"
+			view.power_state = power_state
+			view.startup_time = 0.0
+			# Ignore scans collected while the ROM check was running.
+			rfid_initialized = false
+			power_state_changed.emit(power_state)
+		return
+	if not is_running: view.startup_time += delta
 	if not is_running:
 		model.clock += delta
 	if is_running: