How a team's board behaves

Partial: an absent field is left alone, so a client may send only what changed and two people editing different settings do not overwrite each other. `defaultStateId` additionally distinguishes an empty string (clear it, restoring "the team's lowest-position state") from omission (leave it). `key` is the issue prefix. It is uppercased and trimmed, must be 1-6 letters or digits, and is unique within the workspace — a clash is a 409. Changing it changes the displayed id of EVERY issue in the team, because an issue's id is its team's key plus its own number: GEN-42 becomes ENG-42. Existing links that carry the old id will not resolve. Every value is validated here before the database's CHECK constraints see it, so a bad value is a 400 naming the field rather than a 500. `cyclesEnabled` is the only way a team gets cycles at all — there is no create route. A background job keeps them running on the cadence: it appends the current cycle plus `cycleUpcoming` more, contiguously (or `cycleCooldownDays` apart, if set), and never moves, renames or removes one that already exists — nothing in this API can delete a cycle once the roller has made it. Turning `cyclesEnabled` on from off creates the first cycle immediately rather than waiting for the next hourly tick. Changing the cadence affects only the cycles created after it — the quarter that already happened is not rewritten. `cycleStartDay` aligns only the very first cycle; after that each begins `cycleCooldownDays` after the previous ends, so the rhythm cannot drift or leave a gap beyond the one asked for. `cycleRollover` moves an unfinished issue into the next cycle the moment its own cycle ends; completed and canceled issues stay where they are, since they are that cycle's record of what happened, not work still open. Off by default. Turning it on from off closes out every cycle that has already ended, so the very next rollover only ever affects cycles that end from here on — it does not walk months of already-finished cycles forward into the one running now. Requires org.teams.manage, or leading this team.