docs: sync READMEs with 1.6.0 (remote SSH, session manager, permissions); fix installer prompts under curl|bash

README.md + README.zh-CN.md:
- New "Remote SSH Sessions" section (durable remote tmux, auto-reconnect,
  discover/attach with detach-not-kill, shared sessions, injection-safe ssh)
- New "Session Manager & Command Palette" subsection (pinning survives kill,
  name retention on resume, cross-device tab order sync)
- Multi-user quick start right after installation (users add + --multiuser),
  and the zh-CN README gains the full Multi-User Mode section it was missing
- Security: document the configurable startup permission mode (skip/auto/
  normal/allowedTools) and the multi-user auto downgrade
- Cron header button noted as opt-in (Header Displays); API section counts
  refreshed (~190 handlers / 20 route modules) with pin, session-order and
  unified endpoints; Development now recommends npm run test:ci

CLAUDE.md (/init audit): session-order.ts in the Session row, PR #157
session-manager polish appended to the unified-list pattern, opt-in Cron
button documented, route/SSE counts refreshed (20 modules, ~188 handlers,
~146 events)

install.sh: the post-install "How would you like to run Codeman?" menu (and
the CLI picker + yes/no prompts) read from stdin, which under curl | bash is
the pipe, so choices were impossible and the script silently fell through to
the default. New has_tty()/read_reply() helpers prompt via /dev/tty whenever
a real terminal exists (same approach the sudo path already used) and only
fall back to defaults when there is genuinely none, now with an info line
saying so. Verified both paths with a pty harness (script(1)) and setsid.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: claude