refactor(folio): build AppGraph from platform entry points

MainActivity (Android) and MainViewController (iOS) now own the
suspend DriverFactory.create() and feed the resulting LedgerDatabase
into Metro's createGraphFactory<AppGraph.Factory>().

examples/folio/app/shared/src/iosMain/kotlin/app/folio/MainViewController.kt

@@ -2,7 +2,10 @@ package app.folio
 
 import androidx.compose.ui.window.ComposeUIViewController
 import app.folio.core.data.DriverFactory
+import app.folio.db.LedgerDatabase
+import app.folio.di.AppGraph
 import app.folio.ui.IosBackGesture
+import dev.zacsweers.metro.createGraphFactory
 import kotlinx.cinterop.BetaInteropApi
 import kotlinx.cinterop.ExperimentalForeignApi
 import kotlinx.cinterop.ObjCAction
@@ -28,7 +31,10 @@ private val backGestureTarget = BackGestureTarget()
 @OptIn(ExperimentalForeignApi::class)
 fun MainViewController(): UIViewController {
     val driverFactory = DriverFactory()
-    val vc = ComposeUIViewController { App(driverFactory) }
+    val graphFactory = createGraphFactory<AppGraph.Factory>()
+    val vc = ComposeUIViewController {
+        App(graphBuilder = { graphFactory.create(LedgerDatabase(driverFactory.create())) })
+    }
     val gesture = UIScreenEdgePanGestureRecognizer(
         target = backGestureTarget,
         action = NSSelectorFromString("handleGesture:"),