Expand Glitch operations hub, cabinet authoring, deployment, and RFID support

Operator hub
- Introduce Escape Gallery branding and Glitch: the Dark Machine room views
- Add cabinet illustrations, Pac-Man marquee/gameplay artwork, and waiting states
- Add device feedback panels with RFID readings, input/output states, and stale status
- Add logged operator hardware interventions with request deduplication

Room and cabinet authoring
- Add a visual custom-PCB connection editor with per-cabinet device inventory
- Support device IDs, bindings, wiring notes, input polarity, and validation
- Add physical-room label/dimension toggles and editable doorway annotations
- Preserve doorway changes through undo, save, and revert
- Expand cabinet profiles, room layout, and Glitch scenario resources

Scenarios and gameplay
- Add per-assignment game configuration and runtime feature validation
- Add timed test wins and Frogger individual-home objectives
- Add the three-cabinet timed/score/Frogger test scenario
- Add Cabinet 1 Pac-Man RFID credits, credit sound, and CREDIT 0/1 display
- Require physical Start after an accepted scan and prevent duplicate credits

Pi hardware and deployment
- Add GPIO feedback sampling and a separate multiplexed RFID helper
- Validate reader pin ownership and input/output conflicts
- Add SSH cabinet startup and Pi desktop-session service support
- Add master packaging, site setup, SSH enrollment, and staged cabinet releases
- Verify deployment manifests and support explicit activation/status/log commands

Documentation and verification
- Consolidate the root README around the current architecture and setup workflow
- Add the complete master/Pi/RFID export and deployment walkthrough
- Document network isolation, credentials, card identification, and rollback
- Add PCB, room-editor, feedback, credit, deployment, and controller tests
- Isolate protocol tests from designer-edited cabinet configurations

Known limitations
- RFID helper compilation and physical Pi commissioning remain unverified
- Fleet provisioning does not yet configure RFID-only installations completely
- Broader Pac-Man tests retain a ghost-capture assertion failure
- Staged exports must be rebuilt and checked before deploying runtime 2.3

core/runtime/pi_gpio_client.gd

@@ -5,6 +5,8 @@ const URL := "http://127.0.0.1:8765"
 var pending: Array[Dictionary] = []
 var serial := 0
 var busy := false
+var device_feedback: Dictionary = {}
+var feedback_received_ms: int = 0
 var heartbeat: HTTPRequest
 
 func _ready() -> void:
@@ -12,6 +14,7 @@ func _ready() -> void:
 	heartbeat = HTTPRequest.new()
 	heartbeat.timeout = 1.0
 	add_child(heartbeat)
+	heartbeat.request_completed.connect(_feedback_response)
 	var timer := Timer.new()
 	timer.wait_time = 1.0
 	timer.timeout.connect(_heartbeat)
@@ -56,3 +59,18 @@ func _pump() -> void:
 	status_changed.emit("GPIO %s accepted by Pi bridge" % item.payload.pin if ok else message)
 	completed.emit(item.id, ok)
 	_pump.call_deferred()
+
+func _feedback_response(result: int, code: int, _headers: PackedStringArray, body: PackedByteArray) -> void:
+	if result != HTTPRequest.RESULT_SUCCESS or code != 200:
+		return
+	var data = JSON.parse_string(body.get_string_from_utf8())
+	if data is Dictionary and data.get("feedback") is Dictionary:
+		device_feedback = data.feedback
+		feedback_received_ms = Time.get_ticks_msec()
+
+func get_feedback() -> Dictionary:
+	var result := device_feedback.duplicate(true)
+	result["fresh"] = feedback_received_ms > 0 and Time.get_ticks_msec() - feedback_received_ms < 4000
+	for device in result.get("devices", []):
+		device["age_ms"] = int(device.get("age_ms", 999999)) + maxi(0, Time.get_ticks_msec() - feedback_received_ms)
+	return result