pull

Before running the CLI, verify: 1. `lens` binary is on PATH. If `command -v lens` returns non-zero, tell the user: "lens CLI not found. Install with `npm i -g lens-engine`." 2. `lens.yml` exists (use `Bash` tool to test `-f lens.yml`). If not, tell the user: "No `lens.yml` found. Run `/lens:init` first." Then run (passing arguments through verbatim): lens pull $ARGUMENTS `lens pull` invokes the configured runner (an LLM session) and can take a minute or more on larger repos. Stream the CLI's stdout/stderr to the user. If it exits non-zero, surface the error clearly.