feat: unify automatic shell setup

[wendaining]

Summary

• add recall setup as the single idempotent entry point for automatic capture, hooks-only setup, custom profiles, and removal across zsh, bash, fish, and PowerShell
• launch the proxy from a lightweight block at the top of the profile and install hooks at the end, so the user RC body loads once without terminal-emulator configuration
• preserve profile permissions, newline style, BOM/UTF-16 encoding, unmanaged integrations, and safely migrate legacy managed blocks
• extend recall doctor to report managed setup, hooks, proxy state, legacy configuration, and actionable restart guidance
• update Unix and Windows installers/uninstallers and English/Chinese documentation for the unified flow
• add terminal-aware ANSI styling to the Unix installer, with clean fallbacks for redirected output, NO_COLOR, and TERM=dumb
• add a developer harness that packages the current checkout as a local release and runs the unchanged production installer against it, with an isolated sandbox by default

Testing

• cargo fmt --check
• cargo clippy --all-targets
• cargo test
• zsh automatic-start PTY smoke test with active proxy and hooks
• isolated and simulated user-mode runs of scripts/dev-install.sh, including the production logo, archive extraction, checksum verification, setup, configuration, and summary
• ANSI color detection in a PTY plus escape-free redirected and NO_COLOR output
• sh -n, bash -n, and zsh -n for the Unix installer and developer harness

Windows ConPTY runtime coverage remains in CI.

Closes #21