Initial commit — Station 0 vertical slice in progress

Includes full design documentation (ARCHITECTURE, DESIGN_NOTES, CONTENT_SPEC, PRODUCTION_NOTES)
and active Godot 4 / GDScript codebase. Core systems built: player, floor generation,
room system, enemy base, body part upgrades, run manager, save system, HUD, EventBus.

scripts/npcs/npc_manager.gd

@@ -0,0 +1,72 @@
+extends Node
+
+enum NPCState {
+	UNDISCOVERED,
+	IN_HUB,
+	ON_RUN,
+	LOST,
+}
+
+# npc_id -> { state: NPCState, resource_path: String }
+var _registry: Dictionary = {}
+
+func register_npc(npc_id: String, resource_path: String) -> void:
+	if npc_id not in _registry:
+		_registry[npc_id] = {
+			"state": NPCState.UNDISCOVERED,
+			"resource_path": resource_path,
+		}
+
+func discover_npc(npc_id: String) -> void:
+	if npc_id not in _registry:
+		return
+	_registry[npc_id]["state"] = NPCState.IN_HUB
+	var npc := _load_npc(npc_id)
+	if npc:
+		EventBus.npc_saved.emit(npc)
+
+func send_on_run(npc_id: String) -> void:
+	if npc_id in _registry:
+		_registry[npc_id]["state"] = NPCState.ON_RUN
+
+func return_npc_to_hub(npc_id: String) -> void:
+	if npc_id in _registry:
+		_registry[npc_id]["state"] = NPCState.IN_HUB
+
+func lose_npc(npc_id: String) -> void:
+	if npc_id not in _registry:
+		return
+	_registry[npc_id]["state"] = NPCState.LOST
+	var npc := _load_npc(npc_id)
+	if npc:
+		EventBus.npc_lost.emit(npc)
+
+func get_hub_npc_ids() -> Array[String]:
+	var result: Array[String] = []
+	for npc_id in _registry:
+		if _registry[npc_id]["state"] == NPCState.IN_HUB:
+			result.append(npc_id)
+	return result
+
+func get_state(npc_id: String) -> NPCState:
+	return _registry.get(npc_id, {}).get("state", NPCState.UNDISCOVERED)
+
+func get_save_data() -> Dictionary:
+	var data := {}
+	for npc_id in _registry:
+		data[npc_id] = {
+			"state": _registry[npc_id]["state"],
+			"resource_path": _registry[npc_id]["resource_path"],
+		}
+	return data
+
+func load_save_data(data: Dictionary) -> void:
+	_registry.clear()
+	for npc_id in data:
+		_registry[npc_id] = data[npc_id].duplicate()
+
+func _load_npc(npc_id: String) -> Resource:
+	var path: String = _registry[npc_id].get("resource_path", "")
+	if path != "" and ResourceLoader.exists(path):
+		return load(path)
+	return null