--environment cloud sessions gain a --no-monorepo option and a start-up recognition check

What

The --environment flag creates a new cloud session, meaning a Claude Code session running on a remote machine, on a self-hosted environment. Without the interactive screen, this path now changes in several ways:

• --no-monorepo: when the noMonorepo option is set, a default environment ID is used when checking --environment. Before, the environment came only from the environment or pool options.
• Passed on: noMonorepo is sent along with poolId when the cloud session is created. The JSON output still returns pool_id.
• Start-up check: a cloud session now stops with an error up front if it was not recognised as a cloud launch at start-up. The message says "this cloud session launch was admitted without being recognised as one at start-up".
• Error messages about flags that conflict with --environment, such as "--environment cannot be combined with", are now built from a template.
• The fast start path for tmux and worktrees now calls configureFastPathGlobalAgents before checking worktree mode.

Why

If you create cloud sessions with --environment, you can pass --no-monorepo without naming an environment yourself, and a launch that was not set up as a cloud session now fails clearly instead of running.