v0.5.2

Branding controls, group-stage bracket, match page and admin desk.

- Team owners and league admins can set a team's logo and banner by URL as well as by upload, and remove either. Super-admins can take down a player's avatar or banner and a team's logo or banner.
- The bracket tab draws a group stage as a standings table beside its matches: qualifying places are marked with a cut line, the tiebreak rule is stated, Buchholz appears only for Swiss groups, and the elimination-style round columns and connector lines are gone. Match cards are quieter and team names are no longer cut short. A finished playoff shows the champion; the Playoffs tab says who advances while the groups play.
- Match page: the Now card says "Match set for …" once a time is agreed, with a line on when check-in opens; the check-in card appears only while the window is open; the stepper reads "Opponent set" and shows the check-in step on live-scheduled nights; a proposal with one offered time can be accepted straight away and names the proposer.
- Admin desk: the match overview no longer shows "0 – 0" before play and links to the public match page; the matches list drops its paginated footer.

Requires api v0.7.5 (groups → playoffs advancement, dispute detail names) — pinned in deploy/versions.yml.

Pull requests: https://github.com/mtottenh/cg-fe/pull/15, https://github.com/mtottenh/cg-fe/pull/16, https://github.com/mtottenh/cg-fe/pull/17