Manage World Lifecycle

┌─────────────────────────────────────────────────────────┐
│ LOAD                                                     │
│   Main.LoadWorld()                                       │
│   ├─ SDF.Root.DoParse() → parse SDF XML                │
│   ├─ Physics.simulationMode = Script                    │
│   ├─ Import.Loader.Start() → create GameObjects         │
│   ├─ Wait: worldRoot.childCount > 0                     │
│   ├─ PluginStartTracker.Bind(worldRoot)                 │
│   ├─ Physics.SyncTransforms()                           │
│   ├─ Physics.simulationMode = FixedUpdate               │
│   ├─ ResetWorld() [initial reset]                       │
│   └─ Wait: AllStarted == true                           │
├─────────────────────────────────────────────────────────┤
│ RUN                                                      │
│   Normal simulation loop                                 │
│   ├─ FixedUpdate: physics                               │
│   ├─ Update: sensors, UI                                │
│   └─ Plugins: TX/RX threads running                     │
├─────────────────────────────────────────────────────────┤
│ RESET (Ctrl+R)                                           │
│   Main.ResetSimulation()                                 │
│   ├─ SensorRenderManager.Pause()                        │
│   ├─ SimulationWorld.SignalReset()                       │
│   ├─ ResetWorld()                                       │
│   │  ├─ Helper.Base.Reset() for each helper             │
│   │  ├─ Device.Reset() for each device                  │
│   │  └─ CLOiSimPlugin.Reset() for each plugin           │
│   ├─ Wait 0.1s                                          │
│   └─ SensorRenderManager.Resume()                       │
├─────────────────────────────────────────────────────────┤
│ FULL RELOAD (Ctrl+Shift+R)                               │
│   Destroys world root, reloads from SDF                  │
├─────────────────────────────────────────────────────────┤
│ SAVE (Ctrl+Shift+S)                                      │
│   WorldSaver.Update()                                    │
│   ├─ ClearAllComments()                                 │
│   ├─ UpdateGUI() → camera pose                          │
│   ├─ UpdateModels() → model poses, static flags         │
│   └─ UpdateRoads() → road spline points                 │
└─────────────────────────────────────────────────────────┘

// Bind to a loaded world/model root
var tracker = new PluginStartTracker();
tracker.ProgressChanged += OnPluginProgressChanged;   // (started, total)
tracker.AllStartedEvent += OnAllPluginsStarted;        // fires once
tracker.Bind(worldRoot);

// ProgressChanged fires for each plugin that completes OnStart()
// AllStartedEvent fires when StartedCount == TotalCount

Awake()
  └─ OnAwake() [abstract] — set _type, cache components

Start() [coroutine]
  └─ OnStart() [abstract] — register ports, add threads
     ├─ RegisterTxDevice() / RegisterRxDevice()
     ├─ RegisterServiceDevice() / RegisterClientDevice()
     ├─ AddThread(port, threadFunction, device)
     └─ yield return null

  └─ Raises Started event → PluginStartTracker.OnPluginStarted()

// In Main.cs — world is not considered loaded until all plugins start
private void OnAllPluginsStarted()
{
	_pluginAllStarted = true;
	BridgeManager.PrintAllocatedHistory();
}

// LoadWorld() waits in a while loop:
while (!_pluginAllStarted)
	yield return null;

void ResetModel(GameObject targetObject)
{
	// Phase 1: Reset poses (Helper.Base components)
	foreach (var helper in targetObject.GetComponentsInChildren<Helper.Base>())
		helper.Reset();
	// → Restores initial pose via PoseControl
	// → Rewinds animation state

	// Phase 2: Reset devices
	foreach (var device in targetObject.GetComponentsInChildren<Device>())
		device.Reset();
	// → Clears message queues
	// → Resets synthetic timestamps

	// Phase 3: Reset plugins
	foreach (var plugin in targetObject.GetComponentsInChildren<CLOiSimPlugin>())
		plugin.Reset();
	// → Calls OnReset() [virtual]
	// → Plugin-specific state restoration
}

// Triggered by Main.ResetSimulation()
SimulationWorld.SignalReset();
// → Sets _signalReset = true
// → ClientThread sends messages.Param { "reset_simulation": true }
// → External bridge receives and resets its state

// UpdateModels() for each model in scene:
// 1. Remove stale <include> elements
// 2. Remove <model> elements not present in scene
// 3. For each child in WorldRoot:
//    - Get Helper.Model → original model path
//    - Create/update <include> or <model> element
//    - Set <static> from GameObject.isStatic
//    - Set <pose> via Unity2SDF.Pose(position, rotation)

// UpdateRoads() for each road:
// 1. Remove all <road> elements
// 2. Recreate from Main.RoadsRoot children
// 3. Save spline knots as <point> elements

// UpdateGUI() for camera:
// 1. Get Camera.main transform
// 2. Convert to SDF pose via Unity2SDF.Pose()
// 3. Write to <gui><camera><pose>

// Before construction:
Physics.simulationMode = SimulationMode.Script;
// → Physics does NOT run automatically
// → Objects can be positioned without falling

// After construction:
Physics.SyncTransforms();
// → Syncs all manually-set transforms to physics engine
Physics.simulationMode = SimulationMode.FixedUpdate;
// → Normal physics simulation resumes