Canada support: CAD currency and Canadian signup defaults

This release adds support for Canadian companies, with CAD currency available across the web and mobile apps and smarter defaults at signup.

Canadian companies can now sign up with CAD currency and a +1 phone default selected automatically.
CAD is now selectable as your currency in Settings, and Canadian timezones (Halifax, Toronto, Winnipeg, Edmonton, Vancouver) are available during onboarding and in Settings.
Canada is now an option when choosing your billing country and when subcontractors sign up.

Amounts throughout the mobile app — including salary, schedule totals, task details and staff pay — now display in your company's currency instead of a fixed format, matching the web app.
Cost estimates and billing figures in the web app now format correctly for CAD.