fix(webv2): never hydrate the workbench without a project

invokeai/frontend/webv2/src/workbench/workbenchState.test.ts

@@ -471,6 +471,68 @@ describe('generation-device orchestration metadata', () => {
   });
 });
 
+describe('workbench hydration invariants', () => {
+  it('seeds a draft when a projectless session hydrates', () => {
+    const initial = createInitialWorkbenchState();
+    // What `persistEmptySession` caches after the last tab is closed. A load path
+    // that hands this over verbatim used to leave the store with no active project,
+    // which the first consumer to read one dereferences.
+    const emptySession: WorkbenchState = { ...initial, activeProjectId: '', projects: [] };
+
+    const hydrated = workbenchReducer(initial, { state: emptySession, type: 'hydrateWorkbench' });
+
+    expect(hydrated.projects).toHaveLength(1);
+    expect(hydrated.activeProjectId).toBe(hydrated.projects[0]?.id);
+    expect(getActiveProject(hydrated).widgetRegions.left.instanceIds.length).toBeGreaterThan(0);
+  });
+
+  it('builds that draft from the cached account, not the shipped defaults', () => {
+    const initial = createInitialWorkbenchState();
+    const project = getActiveProject(initial);
+    // The account's saved override of the default preset is what an empty cache
+    // still owns; the seeded draft has to inherit it the way the offline load path's
+    // replacement draft does.
+    const customizedDefault = {
+      ...resolveSavedLayoutPreset(initial.account, initial.account.activeLayoutPresetId).snapshot,
+      widgetRegions: {
+        ...project.widgetRegions,
+        left: { ...project.widgetRegions.left, instanceIds: ['generate'] },
+      },
+    };
+    const emptySession: WorkbenchState = {
+      ...initial,
+      account: {
+        ...initial.account,
+        layoutPresetOverrides: { [initial.account.activeLayoutPresetId]: customizedDefault },
+      },
+      activeProjectId: '',
+      projects: [],
+    };
+
+    const hydrated = workbenchReducer(initial, { state: emptySession, type: 'hydrateWorkbench' });
+
+    expect(getActiveProject(hydrated).widgetRegions.left.instanceIds).toEqual(['generate']);
+  });
+
+  it('repairs an active project id that names no hydrated project', () => {
+    const initial = createInitialWorkbenchState();
+    const danglingActiveId: WorkbenchState = { ...initial, activeProjectId: 'project-that-was-refused' };
+
+    const hydrated = workbenchReducer(initial, { state: danglingActiveId, type: 'hydrateWorkbench' });
+
+    expect(hydrated.activeProjectId).toBe(hydrated.projects[0]?.id);
+  });
+
+  it('leaves a populated session alone', () => {
+    const initial = createInitialWorkbenchState();
+
+    const hydrated = workbenchReducer(initial, { state: initial, type: 'hydrateWorkbench' });
+
+    expect(hydrated.projects.map((project) => project.id)).toEqual(initial.projects.map((project) => project.id));
+    expect(hydrated.activeProjectId).toBe(initial.activeProjectId);
+  });
+});
+
 describe('workbench widget region defaults', () => {
   it('starts new projects from the curated Compose widget defaults', () => {
     const state = createInitialWorkbenchState();

invokeai/frontend/webv2/src/workbench/workbenchState.ts

@@ -2348,15 +2348,36 @@ export const normalizeWorkbenchAccount = (value: unknown): WorkbenchState['accou
   };
 };
 
-const normalizeWorkbenchState = (state: WorkbenchState): WorkbenchState => ({
-  ...state,
-  backendConnection: { status: 'connecting' },
+const normalizeWorkbenchState = (state: WorkbenchState): WorkbenchState => {
   // Built explicitly: legacy snapshots carried preferences inside the account
   // (they live in the settings store now) and must not resurface here.
-  account: normalizeWorkbenchAccount(state.account),
-  notifications: [],
-  projects: state.projects.map((project) => normalizeWorkbenchProject(project)),
-});
+  const account = normalizeWorkbenchAccount(state.account);
+  const restored = state.projects.map((project) => normalizeWorkbenchProject(project));
+  // An editor always holds a project: `closeProject` refuses the last tab, and a
+  // session with none is the Home screen, whose cache the load paths are meant to
+  // replace with a fresh draft before handing the state over. One path does not --
+  // when a project the canvas gate refused cannot be retained, the cached snapshot
+  // is returned verbatim, and that cache is projectless whenever the last tab was
+  // closed before the reload. Hydrating it leaves the store's active project
+  // undefined, and the first consumer to read it dereferences undefined rather than
+  // finding an empty editor: the boot widget hint, whose first access happens to be
+  // `widgetRegions`, before the shell renders anything. Seed the draft here, at the
+  // one point every load path passes through, so no snapshot can hydrate without a
+  // project regardless of which path produced it.
+  const projects = restored.length > 0 ? restored : [createDraftProject([], account)];
+  const activeProjectId = projects.some((project) => project.id === state.activeProjectId)
+    ? state.activeProjectId
+    : projects[0]!.id;
+
+  return {
+    ...state,
+    account,
+    activeProjectId,
+    backendConnection: { status: 'connecting' },
+    notifications: [],
+    projects,
+  };
+};
 
 const updateActiveLayout = (
   state: WorkbenchState,