API modules do not need to setup dependency injection.

Move the implementation to the impl modules.

services/appnavstate/impl/src/main/kotlin/io/element/android/services/appnavstate/impl/DefaultActiveRoomsHolder.kt

@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2025 Element Creations Ltd.
+ * Copyright 2025 New Vector Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+package io.element.android.services.appnavstate.impl
+
+import dev.zacsweers.metro.AppScope
+import dev.zacsweers.metro.ContributesBinding
+import dev.zacsweers.metro.SingleIn
+import io.element.android.libraries.matrix.api.core.RoomId
+import io.element.android.libraries.matrix.api.core.SessionId
+import io.element.android.libraries.matrix.api.room.JoinedRoom
+import io.element.android.services.appnavstate.api.ActiveRoomsHolder
+import java.util.concurrent.ConcurrentHashMap
+
+@SingleIn(AppScope::class)
+@ContributesBinding(AppScope::class)
+class DefaultActiveRoomsHolder : ActiveRoomsHolder {
+    private val rooms = ConcurrentHashMap<SessionId, MutableSet<JoinedRoom>>()
+
+    override fun addRoom(room: JoinedRoom) {
+        val roomsForSessionId = rooms.getOrPut(key = room.sessionId, defaultValue = { mutableSetOf() })
+        if (roomsForSessionId.none { it.roomId == room.roomId }) {
+            // We don't want to add the same room multiple times
+            roomsForSessionId.add(room)
+        }
+    }
+
+    override fun getActiveRoom(sessionId: SessionId): JoinedRoom? {
+        return rooms[sessionId]?.lastOrNull()
+    }
+
+    override fun getActiveRoomMatching(sessionId: SessionId, roomId: RoomId): JoinedRoom? {
+        return rooms[sessionId]?.find { it.roomId == roomId }
+    }
+
+    override fun removeRoom(sessionId: SessionId, roomId: RoomId) {
+        val roomsForSessionId = rooms[sessionId] ?: return
+        roomsForSessionId.removeIf { it.roomId == roomId }
+    }
+
+    override fun clear(sessionId: SessionId) {
+        val activeRooms = rooms.remove(sessionId) ?: return
+        for (room in activeRooms) {
+            // Destroy the room to reset the live timelines
+            room.destroy()
+        }
+    }
+}