fix(pty): strip device-query requests and drain leaked stdin responses

[jexShain]

Summary

• Problem: 终端设备查询响应（CPR/DA/DSR）泄漏进 stdin，被 rustyline 当作按键读入，输入行被注入乱码（如 0;115;0cRRR）。详见 [Bug]: 终端设备查询响应泄漏进 stdin，破坏输入行（乱码注入） #434。
• Changes: 双层防御——输出端剥离转发的 query 请求（源头阻止响应），输入端 readline 前进 raw 模式 drain 残留响应（兜底清理）。
• Related Issue: [Bug]: 终端设备查询响应泄漏进 stdin，破坏输入行（乱码注入） #434

Change Type

• Bug fix

Scope

• Core shell / PTY

User-visible Changes

修复远程 ssh/telnet 会话、tmux/screen、man/less 等场景下输入行被终端响应乱码污染的问题。用户不再需要在 prompt 里手动清除 0;115;0c 之类的残留片段。

Compatibility

• Backward compatible? Yes
• Config changes? No

Testing

• cargo test -p aish-pty strip_device_queries → 7/7
• cargo test -p aish-shell report_prefix → 8/8
• cargo clippy -p aish-pty --all-targets -- -D warnings → 零警告
• cargo clippy -p aish-shell --all-targets -- -D warnings → 零警告
• PTY + termios 实验：验证 canonical（ICANON）模式下 poll() 对无换行的 report 返回不可读，raw 模式下可读——确认输入端必须在 poll 前进 raw 模式

Checklist

• Code follows project style
• Tests added if needed
• Documentation updated if needed

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实现细节

1. 输出端（aish-pty write_stdout_all）：剥离转发到真实终端的设备查询 请求（CPR/DA1/DA2/DA3/DSR），从源头阻止真实终端被诱导响应。真正的 TUI/远程程序（vim/less/ssh…）走 passthrough 透传，标志由 bool 改为引用计数 AtomicUsize，修正嵌套/并发命令下内层 guard 提前关闭的隐患。

2. 输入端（aish-shell drain_terminal_responses）：每次 readline 前（含 multiline 续行 > ）进 raw 模式 + O_NONBLOCK 再 poll stdin。raw 模式必须在 poll 前——canonical 模式只按行释放输入，而 report 无行分隔符，poll 否则永远看不到。残留响应则丢弃前导完整 report 序列，剩余用户 type-ahead 用 TIOCSTI 重新注入；TIOCSTI 被内核禁用且非 report 字节丢失时记 warn（tail_len/reinjected）。

strip_device_queries 区分 请求 与 响应：请求 private marker 只认 >/=（不认 ?），避开误删 DA1 响应 ESC[?64;1c；响应参数带 ; 自然落出 digit 扫描而被保留。

Fixes #434

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[coderabbitai]

📝 Walkthrough

Walkthrough

The change filters terminal query requests from normal PTY output and drains leaked terminal responses before readline. Interactive and session commands retain raw output through nested guards. The shell preserves remaining type-ahead when it removes terminal responses.

Changes

Terminal response handling

Layer / File(s)	Summary
PTY output filtering crates/aish-pty/src/persistent.rs	Normal output strips CPR, DSR, and DA query requests. Interactive and session commands enable nested raw-output passthrough. Tests cover filtering and preservation cases.
Terminal response draining crates/aish-shell/src/keyboard/raw_mode.rs, crates/aish-shell/src/keyboard/mod.rs	The shell drains leading terminal reports from stdin, reinjects remaining type-ahead through TIOCSTI, restores terminal settings, and provides Unix and non-Unix APIs.
Readline integration crates/aish-shell/src/readline.rs	Readline entry points drain leaked CPR and DA responses before invoking rustyline, including multiline continuation reads.

Estimated code review effort: 4 (Complex) | ~45 minutes

Sequence Diagram(s)

sequenceDiagram
  participant PTY
  participant Terminal
  participant Readline
  participant stdin
  PTY->>Terminal: filter normal query requests
  PTY->>Terminal: pass through interactive/session output
  Terminal->>stdin: return terminal reports
  Readline->>stdin: drain leading reports before reading
  Readline->>Readline: invoke rustyline with preserved type-ahead

Loading

Possibly related PRs

• AI-Shell-Team/aish#186: Modifies PTY command execution and readline integration for interactive terminal I/O.
• AI-Shell-Team/aish#241: Modifies the persistent PTY interactive command flow.
• AI-Shell-Team/aish#338: Modifies readline input handling around interactive prompt processing.

Poem

A rabbit filters queries at night,
And drains stray reports from sight.
Type-ahead hops safely back in line,
While rustyline reads input fine.
Interactive output still runs free—
Hop, hop, clean terminal harmony.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	The changes implement both protections requested by issue #434, including query stripping, response draining, type-ahead preservation, and passthrough tracking.
Out of Scope Changes check	✅ Passed	All changes support issue #434 by implementing, integrating, testing, or platform-supporting the terminal query and response handling.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly summarizes the primary changes: stripping PTY device queries and draining leaked stdin responses.

✨ Finishing Touches

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• Create PR with unit tests

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[coderabbitai]

Actionable comments posted: 4

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@crates/aish-pty/src/persistent.rs`:
- Around line 100-124: Make device-query filtering stream-aware in both sites:
update strip_device_queries in crates/aish-pty/src/persistent.rs (lines 100-124)
to preserve incomplete CSI query candidates across PTY reads, resolving them
only when subsequent bytes confirm or reject the sequence while writing output
in order; update the raw-mode input handling in
crates/aish-shell/src/keyboard/raw_mode.rs (lines 104-108) to retain incomplete
report candidates across stdin reads and prevent their prefixes from reaching
rustyline until resolved.

In `@crates/aish-shell/src/keyboard/raw_mode.rs`:
- Around line 179-203: The report_prefix_len parser currently treats query
request sequences ending in n or t as discardable responses. Restrict
recognition to valid terminal response parameter shapes, excluding requests such
as ESC[5n, ESC[6n, and ESC[18t, while preserving existing response handling; add
tests asserting each request returns a prefix length of zero.
- Around line 91-104: Update the input-draining flow around
InputRawGuard::enter, set_stdin_nonblocking, stdin_readable_now, and
read_pending so raw mode and nonblocking I/O are established before the
readiness probe. Preserve the zero-timeout poll before any read, and return
early when no input is readable or raw-mode setup fails.

In `@crates/aish-shell/src/readline.rs`:
- Around line 747-750: Ensure crate::keyboard::drain_terminal_responses() runs
immediately before every readline call, including the continuation readline path
in the multiline input flow. Preserve the existing initial-prompt cleanup and
add the same cleanup to the continuation path so pending terminal responses
cannot reach rustyline.

🪄 Autofix

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 1764a7e2-2f0c-4fb7-883d-3878935a128a

📥 Commits

Reviewing files that changed from the base of the PR and between 06f2347 and cf2abd1.

📒 Files selected for processing (4)

• crates/aish-pty/src/persistent.rs
• crates/aish-shell/src/keyboard/mod.rs
• crates/aish-shell/src/keyboard/raw_mode.rs
• crates/aish-shell/src/readline.rs

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Note

GitHub couldn't provide a complete incremental comparison for this pull request, so CodeRabbit is performing a full review instead. This review may take a little longer.