guilds worker: Street Soccer Pro guild storage and live hub

every /v1 route is POST with a guilds.v1 protobuf body (proto/guilds.proto), Content-Type application/x-protobuf,
Authorization: Bearer GUILDS_TOKEN; domain outcomes are 200 with a protobuf response whose result = guild.RESULT;
400 malformed, 401 auth, 5xx failure, as plain text. X-Body-Encoding: base64 carries both bodies as base64 text.

  /v1/players  /v1/guild  /v1/browse  /v1/search  /v1/top  /v1/check  /v1/reserve  /v1/purchase  /v1/create
  /v1/join  /v1/cancel  /v1/answer  /v1/leave  /v1/disband  /v1/member  /v1/settings  /v1/xp  /v1/live  /v1/erase

POST /roblox/webhook takes Roblox webhook JSON signed with roblox-signature.