refactor(mobile): each new-task draft route keeps its own flow state

apps/mobile/src/App.tsx

@@ -75,6 +75,7 @@ import {
   linkToRootPath,
   rootNavigationRef,
 } from "./lib/rootNavigation";
+import { pruneNewTaskFlowStates } from "./features/threads/new-task-flow-state";
 import { pruneNewTaskBranchCheckouts } from "./features/threads/NewTaskDraftRouteScreen";
 
 import "../global.css";
@@ -133,6 +134,7 @@ function handleNavigationStateChange(state: NavigationState | undefined): void {
   if (!state) return;
   setAgentNotificationPathname(workspaceLocationFromState(state).pathname);
   recordAppShortcutNavigationState(state);
+  pruneNewTaskFlowStates(state);
   pruneNewTaskBranchCheckouts(state);
   pruneIncomingShareImports(state);
 }

apps/mobile/src/Stack.tsx

@@ -89,6 +89,7 @@ import {
   NewTaskThreadSettingsRouteScreen,
 } from "./features/threads/ThreadSettingsSheet";
 import { NewTaskFlowProvider } from "./features/threads/new-task-flow-provider";
+import { newTaskFlowKey } from "./features/threads/new-task-flow-state";
 import { NewTaskRouteScreen } from "./features/threads/NewTaskRouteScreen";
 import { SettingsNavigationRouteScreen } from "./features/settings/SettingsNavigationRouteScreen";
 import { SettingsAppearanceRouteScreen } from "./features/settings/SettingsAppearanceRouteScreen";
@@ -500,7 +501,12 @@ function RootStackLayout(props: {
       .slice(0, props.state.index + 1)
       .filter((route) => !isWorkspaceOverlayRoute(route.name)),
   );
-  const draftRoute = props.state.routes.findLast((route) => route.name === "Thread");
+  // The flow follows the draft route even while a pushed Thread covers it, so
+  // its state lives exactly as long as the route.
+  const draftRoute = props.state.routes.findLast(isDraftThreadRoute);
+  const draftRouteOnTop =
+    draftRoute !== undefined &&
+    props.state.routes.findLast((route) => route.name === "Thread") === draftRoute;
   const draftParams = (
     draftRoute?.params as { draft?: { draftId?: string | string[] } } | undefined
   )?.draft;
@@ -509,7 +515,11 @@ function RootStackLayout(props: {
     : draftParams?.draftId;
 
   return (
-    <NewTaskFlowProvider active={isDraftThreadRoute(draftRoute)} routeDraftId={routeDraftId}>
+    <NewTaskFlowProvider
+      active={draftRouteOnTop}
+      flowKey={draftRoute === undefined ? undefined : newTaskFlowKey(draftRoute)}
+      routeDraftId={routeDraftId}
+    >
       <HardwareKeyboardCommandProvider pathname={pathname}>
         <ShowcaseCaptureCoordinator pathname={pathname} />
         <SettingsEnvironmentFilterProvider open={settingsOpen}>

apps/mobile/src/features/threads/NewTaskDraftRouteScreen.tsx

@@ -1,4 +1,3 @@
-import { useNewTaskFlow } from "./new-task-flow-provider";
 import * as Dialog from "../../components/ui/Dialog";
 import {
   CommonActions,
@@ -7,7 +6,7 @@ import {
   usePreventRemoveContext,
   type StaticScreenProps,
 } from "@react-navigation/native";
-import { useEffect, useLayoutEffect, useState } from "react";
+import { useEffect, useState } from "react";
 import { View } from "react-native";
 import { useAtomValue } from "@effect/atom-react";
 import {
@@ -91,13 +90,6 @@ const idleBranchCheckoutAtom = Atom.make(AsyncResult.initial<BranchCheckoutResul
 export function NewTaskDraftRouteScreen({ route }: StaticScreenProps<NewTaskDraftRouteParams>) {
   const currentRoute = useRoute();
   const params = route.params ?? {};
-  const { reset } = useNewTaskFlow();
-  const [initialized, setInitialized] = useState(false);
-  useLayoutEffect(() => {
-    reset();
-    // oxlint-disable-next-line react/set-state-in-effect -- Draft reset runs once before first paint; initialized gates the screen until then.
-    setInitialized(true);
-  }, [reset]);
   const draftId = Array.isArray(params.draftId) ? params.draftId[0] : params.draftId;
   const projects = useProjects();
   const { state: catalogState } = useWorkspaceState();
@@ -201,7 +193,6 @@ export function NewTaskDraftRouteScreen({ route }: StaticScreenProps<NewTaskDraf
   };
   const preparingBranch = checkoutPending || (needsPreparation && result?._tag !== "Success");
 
-  if (!initialized) return null;
   return (
     <>
       {preparingBranch ? (

apps/mobile/src/features/threads/NewTaskDraftScreen.tsx

@@ -61,7 +61,6 @@ import {
   getComposerDraftSnapshot,
   updateComposerDraftSettings,
   scheduleUnusedComposerAttachmentCleanup,
-  waitForComposerDraftsLoaded,
 } from "../../state/use-composer-drafts";
 import { useEnvironmentServerConfig, useProjects } from "../../state/entities";
 import { useProjectClone } from "../../state/projectClones";
@@ -223,10 +222,6 @@ export function NewTaskDraftScreen(props: {
     }
   };
   const deleteProject = useAtomCommand(projectEnvironment.delete, { reportFailure: false });
-  const selectedProjectRef = useRef(selectedProject);
-  useEffect(() => {
-    selectedProjectRef.current = selectedProject;
-  }, [selectedProject]);
   const removeClonedProject = async () => {
     if (!selectedProject) return;
     const removed = selectedProject;
@@ -242,8 +237,7 @@ export function NewTaskDraftScreen(props: {
       );
       return;
     }
-    const current = selectedProjectRef.current;
-    if (current?.id === removed.id && current.environmentId === removed.environmentId) {
+    if (flow.getSelectedProjectKey() === scopedProjectKey(removed.environmentId, removed.id)) {
       navigation.dispatch(StackActions.replace("Home"));
     }
   };
@@ -280,8 +274,12 @@ export function NewTaskDraftScreen(props: {
         project.id === props.initialProjectRef?.projectId,
     ),
   );
+  // A route naming a draft that is gone, or whose project is gone, also
+  // returns to the picker.
+  const isRouteDraftMissing =
+    props.draftId !== undefined && flow.missingRouteDraftId === props.draftId;
   const isProjectPickerReturnActive =
-    isReturningToProjectPicker && !requestedInitialProjectAvailable;
+    (isReturningToProjectPicker && !requestedInitialProjectAvailable) || isRouteDraftMissing;
   const isIncomingShareAwaitingServerConfig = Boolean(
     incomingShare?.attachments.some((attachment) => attachment.type === "file") &&
     selectedEnvironmentServerConfig === null,
@@ -373,12 +371,11 @@ export function NewTaskDraftScreen(props: {
     isIncomingShareUnavailable;
   const appliedInitialProjectKeyRef = useRef<string | null>(null);
   useEffect(() => {
-    if (!isReturningToProjectPicker) {
-      return;
-    }
-    if (requestedInitialProjectAvailable) {
+    if (isReturningToProjectPicker && requestedInitialProjectAvailable) {
       // oxlint-disable-next-line react/set-state-in-effect -- Ends the return-to-picker flow once the requested project arrives from the catalog.
       setIsReturningToProjectPicker(false);
+    }
+    if (!isProjectPickerReturnActive) {
       return;
     }
     // Wait for usePreventRemove to disable before replacing, or the transfer guard swallows the fallback.
@@ -389,41 +386,12 @@ export function NewTaskDraftScreen(props: {
     });
     return () => cancelAnimationFrame(frame);
   }, [
+    isProjectPickerReturnActive,
     isReturningToProjectPicker,
     navigation,
     props.incomingShareId,
     requestedInitialProjectAvailable,
   ]);
-  const { openDraft } = flow;
-  // Cold launches load drafts and projects separately; wait for hydration and retry while shells load.
-  const attemptedDraftIdRef = useRef<string | null>(null);
-  useEffect(() => {
-    if (!props.draftId) {
-      return;
-    }
-    const draftId = props.draftId;
-    if (attemptedDraftIdRef.current === draftId) {
-      return;
-    }
-    let cancelled = false;
-    void waitForComposerDraftsLoaded().then(() => {
-      if (cancelled || attemptedDraftIdRef.current === draftId) {
-        return;
-      }
-      if (openDraft(draftId)) {
-        attemptedDraftIdRef.current = draftId;
-        return;
-      }
-      if (getComposerDraftSnapshot(draftId).project !== undefined && projects.length === 0) {
-        return;
-      }
-      attemptedDraftIdRef.current = draftId;
-      navigation.dispatch(CommonActions.navigate("NewTaskProject"));
-    });
-    return () => {
-      cancelled = true;
-    };
-  }, [navigation, openDraft, projects, props.draftId]);
 
   const lastInitialProjectRefRef = useRef(props.initialProjectRef);
   const initialPickerRef = useRef<"open" | "dismissed" | null>(null);