Add review step for service, location, date/time, and email

[veenupunyani]

PR Summary

• Added a review step that shows the selected service, location, date, and time, plus an editable confirmation email defaulted from the signed-in account.
• Enabled Review on the datetime step only after a timeslot was selected, with Back as the only action on review (no Confirm yet).
• Reused the existing booking callout, back/continue rows, and landing guards. Shared date/time formatting so the callout and datetime labels stayed consistent.

Test plan

1. Complete service → location → login → datetime, pick a slot, and confirm Review is enabled and goes to /review.
2. Confirm the review page shows service, location, date/time, and the login email, and that the email field is editable.
3. Confirm Back returns to datetime and earlier steps still let you change selections.
4. Confirm there is no Confirm button on review.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud