//! Output rendering — tables, progress bars, color, output-mode dispatch.
//! Default = `table` for TTY, `json` for non-TTY (per `.claude/rules/cli-output.md`).
//!
//! T0 lays down the module skeleton. T1 (telemetry) and T2.5 (auth/UI) flesh
//! out the renderers. Anything not yet implemented uses `unimplemented!()` —
//! the dispatcher never reaches those code paths in the stub commands at T0.