Move auth to service, UI/UX improvements

- Service handles auth: auto-login via Quest SDK on onCreate, periodic
  token refresh, isAuthenticated/login AIDL methods
- Clients tab shows actual connected game clients from ClientTracker
  instead of plans filtered by status
- Create Plan service picker shows "YouTube - DisplayName" per linked
  account instead of raw service IDs
- createDefaultPlan AIDL method creates plan with one destination per
  linked account (unlisted)
- Session validation on Activity open via getMe() call
- Backend health indicator (green/red dot) on Dashboard nav icon
- ConnectedClientInfo parcelable for client data over AIDL
- SDK client exposes isAuthenticated, login, createDefaultPlan,
  getConnectedClients, authenticated StateFlow

shared/src/main/aidl/com/omixlab/lckcontrol/shared/ConnectedClientInfo.aidl

@@ -0,0 +1,3 @@
+package com.omixlab.lckcontrol.shared;
+
+parcelable ConnectedClientInfo;

shared/src/main/aidl/com/omixlab/lckcontrol/shared/ILckControlCallback.aidl

@@ -7,4 +7,5 @@ interface ILckControlCallback {
     void onStreamPlanUpdated(in StreamPlan plan);
     void onClientRegistered(String clientId);
     void onClientUnregistered(String clientId);
+    void onAuthStateChanged(boolean authenticated);
 }

shared/src/main/aidl/com/omixlab/lckcontrol/shared/ILckControlService.aidl

@@ -1,21 +1,35 @@
 package com.omixlab.lckcontrol.shared;
 
+import com.omixlab.lckcontrol.shared.ConnectedClientInfo;
 import com.omixlab.lckcontrol.shared.LinkedAccount;
 import com.omixlab.lckcontrol.shared.StreamPlan;
 import com.omixlab.lckcontrol.shared.StreamPlanConfig;
 import com.omixlab.lckcontrol.shared.ILckControlCallback;
 
 interface ILckControlService {
+    // Auth
+    boolean isAuthenticated();
+    void login();
+
+    // Accounts
     List<LinkedAccount> getLinkedAccounts();
+
+    // Stream plans
     StreamPlan createStreamPlan(in StreamPlanConfig config);
+    StreamPlan createDefaultPlan(String clientName);
     StreamPlan prepareStreamPlan(String planId);
     List<StreamPlan> getStreamPlans();
     StreamPlan getStreamPlan(String planId);
     boolean startStreamPlan(String planId);
     boolean endStreamPlan(String planId);
+
+    // Clients
     String registerClient(String clientName, String packageName);
     void unregisterClient(String clientId);
     void setClientActivePlan(String clientId, String planId);
+    List<ConnectedClientInfo> getConnectedClients();
+
+    // Callbacks
     void registerCallback(ILckControlCallback callback);
     void unregisterCallback(ILckControlCallback callback);
 }

shared/src/main/java/com/omixlab/lckcontrol/shared/ConnectedClientInfo.kt

@@ -0,0 +1,33 @@
+package com.omixlab.lckcontrol.shared
+
+import android.os.Parcel
+import android.os.Parcelable
+
+data class ConnectedClientInfo(
+    val clientId: String,
+    val clientName: String,
+    val packageName: String,
+    val activePlanId: String? = null,
+) : Parcelable {
+
+    constructor(parcel: Parcel) : this(
+        clientId = parcel.readString()!!,
+        clientName = parcel.readString()!!,
+        packageName = parcel.readString()!!,
+        activePlanId = parcel.readString(),
+    )
+
+    override fun writeToParcel(parcel: Parcel, flags: Int) {
+        parcel.writeString(clientId)
+        parcel.writeString(clientName)
+        parcel.writeString(packageName)
+        parcel.writeString(activePlanId)
+    }
+
+    override fun describeContents(): Int = 0
+
+    companion object CREATOR : Parcelable.Creator<ConnectedClientInfo> {
+        override fun createFromParcel(parcel: Parcel) = ConnectedClientInfo(parcel)
+        override fun newArray(size: Int) = arrayOfNulls<ConnectedClientInfo>(size)
+    }
+}