vspawn

Explicitly spawn a standalone child session under the current vlx-term session, passing the task in as its first message (mirrors spawn_task). Runs in the current directory by default, without a git worktree (use vspawn-tree for a worktree). Only use when the user explicitly invokes /vspawn or $vspawn; never auto-trigger. This is a real session run by its own process in the vlx-term left-panel tree — not an…