New game type: Hearts

[tsarvs]

What does this PR change?

Adds a new bot game type as well as adds three bots to for a human to play against. Also adds some scripts to scaffold a bot and/or game.

Scope

• This PR touches exactly one of: a single bots/<game-id>/<bot-id>/ directory, games/**,
  or platform code (apps/**, packages/**, tools/**, root config) — not a mix, unless a
  maintainer has applied the maintainer-override label.
• If this PR adds or changes a manifest.json, its id matches the containing directory
  name, and (for bots) its game field matches the bots/<game-id>/ it's grouped under.

For bot submissions

• docker build succeeds against this bot's own directory.
• The bot has been run locally against at least one match.

For game or platform changes

• Tests were added or updated.
• docs/architecture.md and/or the relevant ADR were updated if this changes a core
  abstraction.