ADR 0239: Compact Installation Display

• Status: Accepted
• Date: 2026-10-08
• Task: CLI-402
• Authority: the maintainer reports successful 2.5.1 installation but excessive scrolling and asks for a clearer display based on mature CLI installers.
• Supersedes only ADR 0238's default append-only five-second reporting. Its command, approval, batch, diagnostic-privacy and recovery owners remain intact.

Separate each Host, approval preview, execution and final summary. Preserve all fields of write/registration previews and their confirmations. Default DSH output retains each numbered result and exact failing step, but omits duplicate START, successful launch contexts and captured-output observations. Failures automatically show the existing safe diagnostics and exact commands. --verbose retains full stage/launch diagnostics as append-only output, including the original reason codes; it never reveals raw manager output or credential values.

The shared installation writer owns one temporary, short ASCII status line on recognized Unix terminals with a known width of at least 32 columns. It updates from the existing five-second callback and clears before any ordinary output or prompt. It never moves above its line, clears the screen, hides the cursor or changes terminal input mode. A long-running command shows elapsed/limit time, not an invented download percentage. Only presentation changes: command argv, environment, deadlines, output bounds and Pi's private umask remain unchanged.

--plain, --verbose, NO_COLOR, CI, absent/unsupported TERM, unavailable terminal size, narrow windows and unsupported consoles use append-only output. Compact plain waiting messages are at most once per 30 seconds; verbose retains five-second messages. Non-terminal installation still refuses before writes; display flags do not make interactive approvals scriptable. Existing dry-run and structured query output are unchanged. No new rendering dependency or network service is introduced; Unix size lookup uses the existing rustix crate.

Verification covers real PTY captures, bounded redraws and prompt cleanup, plain/verbose fallbacks, exact approval previews, privacy, failure attribution, batch continuation, EOF/output interruption and parser compatibility. Synthetic managers prove presentation/control flow, not a live Host install or session. Rollback restores the prior renderer without changing installed files/profiles.

Design references: pnpm reporters separate terminal and append-only output; Clack tasks and spinners separate pending tasks and results; GitHub CLI environment options offer verbose diagnostics and accessible progress controls. Qiongli retains its native Rust and explicit approval contracts rather than copying those libraries.