feat(mobile): staged rollback with cross-device session synchronization

src/apps/mobile/harmonyos/AGENTS.md

@@ -100,6 +100,19 @@ fake RPC: send must clear the input before pressing **Acknowledge**, and a
 **Next draft** entered while pending must survive acknowledgment. Exercise both
 compact and wide layouts and return to normal `EntryAbility` afterward.
 
+For rollback reply ownership and session switching, run
+`node --test tools/tests/rollback-session-isolation.test.cjs`.
+In the `copy-rollback` native preview, stage a rollback, use **Resize**, and verify
+the preview remains for the same session. Use **Switch session** and verify the
+staging bar and full-text panel close while `SESSION-B-DRAFT` remains untouched.
+Exercise compact and wide widths in light and dark modes, then restore normal
+`EntryAbility`. Deferred-response unit tests cover switching while rollback,
+send acknowledgment, and voice shutdown are pending; the preview uses a mock
+host and is not evidence of live relay or physical fold behavior.
+After installing the debug HAP on a wide device/emulator, run
+`python3 tools/check-rollback-session-isolation.py --hdc "$HDC" --device <target>`
+for compact/wide, light/dark and live resize checks with layout/screenshot evidence.
+
 For history loading and explicit jump-to-bottom navigation, install the debug
 HAP and run `python3 tools/check-history-scroll.py --hdc "$HDC"`. The
 `history-scroll` preview holds a mock history response while the production

src/apps/mobile/harmonyos/entry/src/main/ets/entryability/EntryAbility.ets

@@ -20,16 +20,21 @@ export default class EntryAbility extends UIAbility {
       scenarioId === 'cold-start-home' || scenarioId === 'cold-start-home-dark' ||
       scenarioId === 'copy-selection' || scenarioId === 'copy-selection-dark' ||
       scenarioId === 'copy-selection-nav' || scenarioId === 'copy-selection-wide' ||
+      scenarioId === 'copy-rollback' || scenarioId === 'copy-rollback-dark' ||
+      scenarioId === 'copy-rollback-send' || scenarioId === 'copy-rollback-send-dark' ||
+      scenarioId === 'copy-rollback-send-fail' || scenarioId === 'copy-rollback-fail' ||
+      scenarioId === 'copy-rollback-fail-dark' || scenarioId === 'copy-rollback-stale' ||
+      scenarioId === 'copy-rollback-busy' || scenarioId === 'copy-rollback-unsupported' ||
       scenarioId === 'interaction-mailbox' || scenarioId === 'interaction-mailbox-dark') {
       this.initialPage = 'pages/preview/MobileDesignGallery';
       this.previewStorage = new LocalStorage();
       this.previewStorage.setOrCreate('scenarioId', scenarioId);
       AppStorage.setOrCreate('scenarioId', scenarioId);
     }
     try {
-      const colorMode = scenarioId === 'cold-start-home-dark' || scenarioId === 'catalog-refresh-dark' || scenarioId === 'model-role-selector-dark' || scenarioId === 'subagent-process-dark' || scenarioId === 'file-visibility-dark' || scenarioId === 'immersive-bottom-dark' || scenarioId === 'immersive-bottom-drawer-dark' || scenarioId === 'immersive-bottom-settings-dark' || scenarioId === 'composer-overflow-dark' || scenarioId === 'composer-overflow-expanded-dark' || scenarioId === 'device-selector-dark' || scenarioId === 'streaming-dark' || scenarioId === 'interaction-mailbox-dark' || scenarioId === 'copy-selection-dark'
+      const colorMode = scenarioId === 'cold-start-home-dark' || scenarioId === 'catalog-refresh-dark' || scenarioId === 'model-role-selector-dark' || scenarioId === 'subagent-process-dark' || scenarioId === 'file-visibility-dark' || scenarioId === 'immersive-bottom-dark' || scenarioId === 'immersive-bottom-drawer-dark' || scenarioId === 'immersive-bottom-settings-dark' || scenarioId === 'composer-overflow-dark' || scenarioId === 'composer-overflow-expanded-dark' || scenarioId === 'device-selector-dark' || scenarioId === 'streaming-dark' || scenarioId === 'interaction-mailbox-dark' || scenarioId === 'copy-selection-dark' || scenarioId === 'copy-rollback-dark' || scenarioId === 'copy-rollback-send-dark' || scenarioId === 'copy-rollback-fail-dark'
         ? ConfigurationConstant.ColorMode.COLOR_MODE_DARK
-        : scenarioId === 'cold-start-home' || scenarioId === 'catalog-refresh' || scenarioId === 'model-role-selector' || scenarioId === 'model-role-selector-wide' || scenarioId === 'subagent-process' || scenarioId === 'file-visibility' || scenarioId === 'immersive-bottom' || scenarioId === 'immersive-bottom-wide' || scenarioId === 'immersive-bottom-drawer' || scenarioId === 'immersive-bottom-settings' || scenarioId === 'immersive-bottom-cover' || scenarioId === 'immersive-bottom-miniapps' || scenarioId === 'immersive-bottom-wide-shell' || scenarioId === 'immersive-bottom-tools' || scenarioId === 'immersive-bottom-tools-editor' || scenarioId === 'immersive-bottom-tools-file-action' || scenarioId === 'immersive-bottom-view-settings' || scenarioId === 'immersive-bottom-connect' || scenarioId === 'composer-overflow' || scenarioId === 'composer-overflow-empty' || scenarioId === 'composer-overflow-wide' || scenarioId === 'composer-overflow-expanded' || scenarioId === 'device-selector' || scenarioId === 'connected-conversation' || scenarioId === 'reconnecting-wide' || scenarioId === 'copy-selection' || scenarioId === 'copy-selection-nav' || scenarioId === 'copy-selection-wide'
+        : scenarioId === 'cold-start-home' || scenarioId === 'catalog-refresh' || scenarioId === 'model-role-selector' || scenarioId === 'model-role-selector-wide' || scenarioId === 'subagent-process' || scenarioId === 'file-visibility' || scenarioId === 'immersive-bottom' || scenarioId === 'immersive-bottom-wide' || scenarioId === 'immersive-bottom-drawer' || scenarioId === 'immersive-bottom-settings' || scenarioId === 'immersive-bottom-cover' || scenarioId === 'immersive-bottom-miniapps' || scenarioId === 'immersive-bottom-wide-shell' || scenarioId === 'immersive-bottom-tools' || scenarioId === 'immersive-bottom-tools-editor' || scenarioId === 'immersive-bottom-tools-file-action' || scenarioId === 'immersive-bottom-view-settings' || scenarioId === 'immersive-bottom-connect' || scenarioId === 'composer-overflow' || scenarioId === 'composer-overflow-empty' || scenarioId === 'composer-overflow-wide' || scenarioId === 'composer-overflow-expanded' || scenarioId === 'device-selector' || scenarioId === 'connected-conversation' || scenarioId === 'reconnecting-wide' || scenarioId === 'copy-selection' || scenarioId === 'copy-selection-nav' || scenarioId === 'copy-selection-wide' || scenarioId === 'copy-rollback' || scenarioId === 'copy-rollback-send' || scenarioId === 'copy-rollback-send-fail' || scenarioId === 'copy-rollback-fail' || scenarioId === 'copy-rollback-stale' || scenarioId === 'copy-rollback-busy' || scenarioId === 'copy-rollback-unsupported'
           ? ConfigurationConstant.ColorMode.COLOR_MODE_LIGHT
           : ConfigurationConstant.ColorMode.COLOR_MODE_NOT_SET;
       this.context.getApplicationContext().setColorMode(colorMode);

src/apps/mobile/harmonyos/entry/src/main/ets/model/RemoteModels.ets

@@ -159,6 +159,11 @@ export interface RemoteCommand {
   reason?: string;
   mode?: RemotePermissionMode;
   answers?: Object;
+  // rollback_session_to_turn: the user turn being withdrawn and the storage
+  // index the caller last saw for it. Omitting the index only widens the race
+  // window; it never changes which turn the host addresses.
+  target_turn_id?: string;
+  expected_storage_turn_index?: number;
   image_contexts?: RemoteImageContext[];
   images?: ImageAttachment[];
   // provision_peer_device. `request_id` is minted by the device being
@@ -361,9 +366,41 @@ export interface SteerTurnResult {
   steeringId: string;
 }
 
+/**
+ * Answer to `rollback_session_to_turn`, sent as `resp: "session_rolled_back"`.
+ *
+ * `retired_turn_ids` includes the target turn itself. `composer_text` is the
+ * prompt the desktop would have put back into its composer, offered so the
+ * client can show the same edit-and-resend continuation; the host omits the key
+ * when it has no prompt to offer. The transcript itself is repaired by the next
+ * poll's authoritative snapshot, not by this answer.
+ */
+export interface SessionRolledBackResponse extends CommandStatusResponse {
+  session_id?: string;
+  retired_turn_ids?: string[];
+  restored_files?: string[];
+  composer_text?: string;
+  changed?: boolean;
+}
+
+/** The decoded rollback answer, with absent host fields kept as absence. */
+export interface SessionRolledBackResult {
+  sessionId: string;
+  retiredTurnIds: string[];
+  restoredFiles: string[];
+  composerText?: string;
+  changed: boolean;
+}
+
 export const REMOTE_CAPABILITY_DIALOG_STEER_V1: string = 'dialog_steer_v1';
 export const REMOTE_CAPABILITY_PLAN_BUILD_V1: string = 'plan_build_v1';
 export const REMOTE_CAPABILITY_HARNESS_PROFILES_V1: string = 'harness_profiles_v1';
+/**
+ * The host can retire a turn and every turn after it, then restore the files
+ * those turns touched (`rollback_session_to_turn`). A host without it answers
+ * the command with an error, so the client checks before offering the entry.
+ */
+export const REMOTE_CAPABILITY_SESSION_ROLLBACK_V1: string = 'session_rollback_v1';
 /** The host resolves `workspace_id` in commands and stamps it on its projections. */
 export const REMOTE_CAPABILITY_WORKSPACE_ID_REFERENCES_V1: string = 'workspace_id_references_v1';
 

src/apps/mobile/harmonyos/entry/src/main/ets/pages/actions/ConversationIntent.ets

@@ -26,6 +26,9 @@ export enum ConversationIntentType {
   OpenFilePreview = 'open_file_preview',
   DownloadFile = 'download_file',
   BuildPlan = 'build_plan',
+  RollbackSession = 'rollback_session',
+  RollbackResync = 'rollback_resync',
+  RollbackNotice = 'rollback_notice',
   Send = 'send',
   VoiceInput = 'voice_input',
   ChatInputChanged = 'chat_input_changed'
@@ -41,6 +44,26 @@ export class PlanBuildRequest {
   }
 }
 
+/**
+ * One staged rollback the view asks the host for.
+ *
+ * `sendText` is what makes the two exits one command: an empty value is the plain
+ * confirm, which leaves the composer alone, while a non-empty value is the
+ * send-while-staging exit, where the rollback has to complete before that text is
+ * sent from the withdrawn point. Both travel together because the order between
+ * them is the whole contract and splitting them into two intents would let a
+ * caller reverse it.
+ */
+export class SessionRollbackRequest {
+  readonly targetTurnId: string;
+  readonly sendText: string;
+
+  constructor(targetTurnId: string, sendText: string = '') {
+    this.targetTurnId = targetTurnId;
+    this.sendText = sendText;
+  }
+}
+
 /**
  * What a `CopyMessage` intent asks the clipboard owner to write.
  *
@@ -65,6 +88,10 @@ export class ConversationIntent {
   readonly answers?: ConversationUiQuestionAnswer;
   readonly filePreviewRequest?: FilePreviewRequest;
   readonly planBuildRequest?: PlanBuildRequest;
+  // Assigned by the factory rather than through the constructor, the same way
+  // `mailboxAction` is: the class's positional constructor is already long, and a
+  // payload only one intent type reads does not belong in every other one's call.
+  rollbackRequest?: SessionRollbackRequest;
   readonly copyScope: MessageCopyScope;
   mailboxAction?: InteractionMailboxAction;
 
@@ -154,4 +181,30 @@ export class ConversationIntents {
       new PlanBuildRequest(path, name)
     );
   }
+
+  /**
+   * The one rollback intent, for both staged exits.
+   *
+   * `sendText` is empty for a confirm and non-empty for send-while-staging; the
+   * host command itself is identical, and the viewmodel decides whether a message
+   * follows it.
+   */
+  static rollback(targetTurnId: string, sendText: string = ''): ConversationIntent {
+    const intent = new ConversationIntent(ConversationIntentType.RollbackSession);
+    intent.rollbackRequest = new SessionRollbackRequest(targetTurnId, sendText);
+    return intent;
+  }
+
+  /** Refetch the authoritative transcript after a host outcome this client refused. */
+  static rollbackResync(): ConversationIntent {
+    return new ConversationIntent(ConversationIntentType.RollbackResync);
+  }
+
+  /**
+   * Say one refusal out loud. The value is a dotted i18n key, not a sentence: the
+   * policy owns which key a given denial resolves to and this app owns no copy.
+   */
+  static rollbackNotice(key: string): ConversationIntent {
+    return new ConversationIntent(ConversationIntentType.RollbackNotice, key);
+  }
 }

src/apps/mobile/harmonyos/entry/src/main/ets/pages/actions/ConversationIntentDispatcher.ets

@@ -1,7 +1,7 @@
 import { InteractionMailboxAction } from '../../model/InteractionMailbox';
 import { RemoteQuestionAnswerPayload, RemoteSession } from '../../model/RemoteModels';
 import { AppRoute, AppRouteContract } from '../navigation/AppRouteContract';
-import { ConversationIntent, ConversationIntentType, MessageCopyScope } from './ConversationIntent';
+import { ConversationIntent, ConversationIntentType, MessageCopyScope, SessionRollbackRequest } from './ConversationIntent';
 import { toRemoteQuestionAnswer } from '../state/ConversationUiModels';
 import { FilePreviewRequest } from '../../model/FilePreviewTarget';
 
@@ -26,6 +26,17 @@ export interface ConversationIntentDispatcherHooks {
   readonly openFilePreview: (route: AppRoute, request: FilePreviewRequest) => void;
   readonly downloadFile: (path: string) => void;
   readonly buildPlan: (path: string, name: string) => Promise<void>;
+  /**
+   * Run one staged rollback against the host.
+   *
+   * It resolves only when the host has answered, because a send-while-staging
+   * exit has to append its message after the turn the rollback retired.
+   */
+  readonly rollback: (request: SessionRollbackRequest) => Promise<void>;
+  /** Refetch the transcript when a host outcome left this client unsure. */
+  readonly rollbackResync: () => Promise<void>;
+  /** Show one rollback refusal, keyed by i18n key. */
+  readonly rollbackNotice: (key: string) => void;
   readonly send: () => Promise<void>;
   readonly voiceInput: () => Promise<void>;
   readonly inputChanged: (route: AppRoute, value: string) => void;
@@ -70,6 +81,10 @@ export class ConversationIntentDispatcher {
           void this.hooks.buildPlan(intent.planBuildRequest.path, intent.planBuildRequest.name);
         }
         return;
+      case ConversationIntentType.RollbackSession:
+        if (intent.rollbackRequest) void this.hooks.rollback(intent.rollbackRequest); return;
+      case ConversationIntentType.RollbackResync: void this.hooks.rollbackResync(); return;
+      case ConversationIntentType.RollbackNotice: this.hooks.rollbackNotice(intent.value); return;
       case ConversationIntentType.Send: void this.hooks.send(); return;
       case ConversationIntentType.VoiceInput: void this.hooks.voiceInput(); return;
       case ConversationIntentType.ChatInputChanged: this.hooks.inputChanged(route, intent.value); return;

src/apps/mobile/harmonyos/entry/src/main/ets/pages/components/ChatMessageBubble.ets

@@ -39,17 +39,24 @@ export struct ChatUserMessageRow {
     detail: ''
   };
   @Param showRetryAction: boolean = false;
+  /** Whether the staged rollback's preview covers this row. See ChatTimeline. */
+  @Param ghost: boolean = false;
   @Event onCopyMessage: (text: string) => void = (_text: string) => {};
-  @Event onOpenFullText: (text: string) => void = (_text: string) => {};
+  @Event onOpenFullText: (text: string, turnId: string) => void =
+    (_text: string, _turnId: string) => {};
   @Event onRetryMessage: (text: string) => void = (_text: string) => {};
+  @Event onRollbackMessage: (turnId: string, text: string) => void =
+    (_turnId: string, _text: string) => {};
 
   build() {
     ChatUserMessageBubble({
       item: this.item,
       showRetryAction: this.showRetryAction,
+      ghost: this.ghost,
       onCopyMessage: this.onCopyMessage,
       onOpenFullText: this.onOpenFullText,
-      onRetryMessage: this.onRetryMessage
+      onRetryMessage: this.onRetryMessage,
+      onRollbackMessage: this.onRollbackMessage
     })
   }
 }
@@ -84,7 +91,18 @@ export struct ChatMessageBubble {
   @Event onCopyMessage: (text: string) => void = (_text: string) => {};
   @Event onCopyMessageScoped: (text: string, scope: MessageCopyScope) => void =
     (_text: string, _scope: MessageCopyScope) => {};
-  @Event onOpenFullText: (text: string) => void = (_text: string) => {};
+  @Event onOpenFullText: (text: string, turnId: string) => void =
+    (_text: string, _turnId: string) => {};
+  /**
+   * The rollback entry, forwarded for the user-authored bubbles this row draws.
+   *
+   * A steering message is drawn with the user bubble, so it carries the entry
+   * too. It has no turn of its own, which is why the entry is wired rather than
+   * hidden: the tap reaches the pane and is answered out loud, instead of a menu
+   * item that silently does nothing.
+   */
+  @Event onRollbackMessage: (turnId: string, text: string) => void =
+    (_turnId: string, _text: string) => {};
   @Event onRetryMessage: (text: string) => void = (_text: string) => {};
   @Event onOpenFilePreview: (path: string, label: string) => void = (_path: string, _label: string) => {};
   @Event onBuildPlan: (path: string, name: string) => void = (_path: string, _name: string) => {};
@@ -381,7 +399,8 @@ export struct ChatMessageBubble {
           item: this.steeringMessage(entry, path),
           showRetryAction: false,
           onCopyMessage: this.onCopyMessage,
-          onOpenFullText: this.onOpenFullText
+          onOpenFullText: this.onOpenFullText,
+          onRollbackMessage: this.onRollbackMessage
         })
       } else if (this.isThinkingEntry(entry)) {
         this.Thinking(