Decide: retire the legacy readline `attach` path (keep the one-shot CLI commands)?

[saucam]

Context

#122 hardened the streaming renderer in the legacy readline client (src/terminal/client.ts, the attach path) by extracting renderStreamMessage and sanitizing untrusted fields. While reviewing it, the real question surfaced: should that interactive path exist at all, or is it dead weight we're now maintaining a bespoke renderer + sanitizer for?

Current state

TerminalClient (src/terminal/client.ts) does two unrelated jobs, wired into src/cli.ts:

1. Interactive readline attach — attachSession() + the streaming render loop (renderStreamMessage). This is the oldest of four ways to watch a session stream, and is redundant with all of them:

   • codeoid-tui (native Rust/Ratatui, recommended cockpit — separate repo)
   • codeoid tui (in-repo Ink cockpit, already documented as the "legacy fallback")
   • Web UI
   • Telegram

   It is also the only part of the file carrying the terminal-escape rendering surface fix: sanitize untrusted output in the legacy readline terminal client (terminal/client.ts) #92 / fix: sanitize untrusted output in the legacy readline terminal client #122 addressed.

2. One-shot request/response commands — ls, new, send, interrupt, approve, destroy. Each connects, sends one message, prints a line, disconnects. Scriptable, pipe-friendly, and with no cockpit equivalent (the cockpits are interactive-only). Worth keeping.

Options

A. Keep as-is (status quo after #122).
Retain codeoid attach and its sanitized renderer.
Cost: maintain a bespoke stream renderer + escape sanitizer indefinitely for a path three richer clients already cover.

B. Remove the interactive attach path; keep the one-shot commands. (Proposed)
Delete attachSession(), renderStreamMessage, the SGR/render helpers, and src/tests/terminal-client-render.test.ts. Drop the codeoid attach command or repoint it to codeoid tui. TerminalClient slims to a thin one-shot WS client for the six scriptable commands.
Benefit: eliminates the terminal-escape surface by removal rather than by maintaining a sanitizer; less code; one fewer renderer to keep in sync with the wire protocol.
Cost / to confirm:

• Loses the plain, pipe-friendly, over-SSH "stream one session to stdout" niche (codeoid tui uses the alt-screen and isn't pipe-friendly).
• Docs/recipes reference it — the README device-handoff example (laptop$ codeoid attach oracle) and possibly external demo recipes — those need updating.

C. Remove TerminalClient entirely (including the one-shots).
Not recommended: the six one-shot commands have no equivalent and would need rewriting against some WS client. TuiWsClient is coupled to a React dispatch, so this just rebuilds a minimal one-shot client anyway.

Recommendation

Option B. It's the cleanest outcome: the streaming path that motivated #92/#122 goes away, the genuinely useful scriptable commands stay, and the terminal-injection concern is closed by deletion instead of an ongoing sanitization burden.

Loose end (either way)

listSessions() / #formatStatus print session name/workdir with raw console.log and were never sanitized (out of #122's scope). Low risk — a user's own session names — and it's moot for the streaming concern under B.

Refs

• fix: sanitize untrusted output in the legacy readline terminal client #122 (merged) — hardened the readline attach renderer
• fix: sanitize untrusted output in the legacy readline terminal client (terminal/client.ts) #92 — the readline-client escape follow-up
• Code: src/terminal/client.ts, src/cli.ts (7 TerminalClient call sites), src/tui/ (the in-repo cockpit)