Weekly cycle moves from Monday start to Tuesday start

**Decision:** the weekly cycle moves from a Monday start to a **Tuesday start**. A week now runs Tuesday through the following Monday. **Going forward only.** No historical recompute. Everything already stamped against a Monday-start week stays exactly as it is. Anything published for the new week onward uses the Tuesday boundary and keeps it for that week. ## What has to move together Every place that currently computes, stamps or snaps to a Monday: - The week key on Culture Feed posts (currently a Monday date) - `required_week`, which gates whether a card counts toward completion - The admin week picker, which force-snaps any value to a Monday on open and on change - The Today read, which keys on the current week - The consumer week computation - Weekly counts, progress and the serving readout **The risk if one is missed:** content lands in a week nobody is serving, and it fails silently. Exactly the shape of the required-week failure — no error, no log, curator believes the week is set, associates receive nothing. Every one of these moves in the same change or none of them do. ## Two things still to decide **Which Tuesday is the first one.** Needs a date. **Whether the changeover week is short or long.** Cutting over on a Tuesday leaves the final Monday-start week running six days. Cutting over the following Monday makes the current week eight. Either is fine, but whoever publishes needs to know which, so they don't schedule a full required set into a six-day window. ## Worth doing at the same time The current week is computed from the **device clock**, not server-side, so the boundary already moves at each person's local midnight rather than at a single company moment. Changing which day it falls on without fixing where it is computed leaves the new boundary just as fuzzy as the old one. Since this change touches every place that calculates the week anyway, it is the natural moment to move that computation server-side. ## Nothing changes for the associate One feed, one Today, same cadence. The only visible difference is which day new content appears.