fix(web): undo step's redo check must restore the exact pre-undo schedule

Phase 2 previously advanced on any schedule change away from the
post-undo snapshot, so a manual re-edit of Dentist (not an actual
redo) would false-positive the mission complete. Compare against the
original step-entry snapshot instead - a genuine redo always restores
it exactly, while a manual re-edit essentially never reproduces the
same timestamps. Also spells out the real redo binding (Mod+Shift+Z)
in the card copy, which previously only showed Mod+Z.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Author: tyler-dane

packages/web/src/components/OnboardingTour/onboarding.tour.steps.ts

@@ -85,7 +85,7 @@ export function getOnboardingTourSteps(): OnboardingTourStep[] {
     },
     undo: {
       title: "Never stress about a mistake",
-      body: "Undo your changes to Dentist, then redo them.",
+      body: "Undo your changes to Dentist with Mod+Z, then bring them back with Mod+Shift+Z.",
       shortcutHint: ["Mod", "Z"],
     },
     hardcore: {

packages/web/src/components/OnboardingTour/useOnboardingTourProgress.test.ts

@@ -279,7 +279,18 @@ describe("useOnboardingTourProgress mission verification", () => {
     });
     expect(useOnboardingTourStore.getState().stepId).toBe("undo");
 
-    // Phase 2: the reapply.
+    // A manual re-edit that changes the schedule again, but not back to the
+    // exact pre-undo value, must not be mistaken for a real redo.
+    act(() => {
+      seedDentist(
+        queryClient,
+        "2026-05-05T18:00:00.000-05:00",
+        "2026-05-05T19:00:00.000-05:00",
+      );
+    });
+    expect(useOnboardingTourStore.getState().stepId).toBe("undo");
+
+    // Phase 2: the reapply - restores exactly the pre-undo schedule.
     act(() => {
       seedDentist(
         queryClient,

packages/web/src/components/OnboardingTour/useOnboardingTourProgress.ts

@@ -99,7 +99,6 @@ export function useOnboardingTourProgress() {
   const scheduleAtEntryRef = useRef<TimedSchedule | null>(null);
   /** undo has two phases: wait for a revert, then wait for a reapply. */
   const undoPhaseRef = useRef<"pending-undo" | "pending-redo">("pending-undo");
-  const undoAfterRevertRef = useRef<TimedSchedule | null>(null);
 
   // create / save / editSequence: unchanged encouragement-based checks.
   useEffect(() => {
@@ -255,7 +254,6 @@ export function useOnboardingTourProgress() {
   useEffect(() => {
     if (!isActive || stepId !== "undo") return;
     enterDentistMission(dentistEvent, scheduleAtEntryRef);
-    undoAfterRevertRef.current = null;
     undoPhaseRef.current = "pending-undo";
   }, [isActive, stepId]);
 
@@ -267,13 +265,15 @@ export function useOnboardingTourProgress() {
 
     if (undoPhaseRef.current === "pending-undo") {
       if (!sameSchedule(current, entry)) {
-        undoAfterRevertRef.current = current;
         undoPhaseRef.current = "pending-redo";
       }
       return;
     }
 
-    if (!sameSchedule(current, undoAfterRevertRef.current)) {
+    // Redo must restore exactly the schedule captured at step entry - not
+    // merely "changed again" - or a manual re-edit of Dentist (rather than
+    // pressing redo) would be misread as a successful redo.
+    if (sameSchedule(current, entry)) {
       onboardingTourActions.advance();
     }
   }, [isActive, stepId, dentistEvent]);