boards worker: Street Soccer Pro leaderboards (players by stat, goals by country each week)

Every route takes Authorization: Bearer INGEST_TOKEN and a universe id (game.GameId); each universe (prod, lab, ...) keeps
its own boards, and only those in UNIVERSES are served (403 otherwise).

POST /v1/players  boards.v1.PlayersRequest protobuf (proto/boards.proto), Content-Type application/x-protobuf.
                  Raises each player's value (never lowers it), keeps their name and country when given, answers the
                  top 100 of every board named. exact = true sets values as given and removes value 0 (dev panel).
POST /v1/nations  boards.v1.NationsRequest protobuf. Adds each week's counts once per batch id, answers the asked
                  week's top countries; result 0 = added or nothing to add, 1 = batch seen before.
POST /v1/seed     JSON {universe, boards: [{board, players: [{user, value, name, nation}]}], nations: {week, counts: [{nation, goals}]}}
                  from tools/boards.luau: players raised as on /v1/players, nation counts set as the week's legacy part.

400 malformed, 401 auth, 5xx failure, as plain text. X-Body-Encoding: base64 carries protobuf bodies as base64 text.