Teams

Teams feature - team code, team list, etc
Logic for team code - generate hash that can be shared via WhatsApp or Email or Telegram, and in team input verify hash exists in a table with schema "TEAMNAME | TEAMMATENO | TEAMHASH" if exists, check if teamname has members > 2, if > 2 then say team full, else increment TEAMMATENO and add membername to db

- [ ] Base feature

Start by locating the team input flow and the database schema or entry point for the TEAMNAME, TEAMMATENO, and TEAMHASH fields. Define the team-code sharing and membership checks, including the limit of two members, then verify that a valid code adds a member and a full team is rejected.

Written by the indexing model from the issue text.