[BUG] Agent View: attached session scroll completely broken on macOS (Ghostty + Warp)

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report
• [x] I am using the latest version of Claude Code (2.1.143)

What's Wrong?

When a session is attached via Agent View on macOS, all built-in scroll mechanisms become unresponsive:

• PgUp / PgDn (Fn+↑ / Fn+↓ on MacBook): no effect
• Ctrl+O transcript mode: opens, but inside transcript view j, k, Space, b, g, G, Ctrl+F, Ctrl+B, PgUp, PgDn all fail to scroll
• [ shortcut to dump conversation to terminal scrollback: inserted as literal text into input box

Any output longer than the viewport becomes effectively unreadable inside attached Agent View sessions.

What Should Happen?

Per documentation, fullscreen sessions should respond to PgUp/PgDn for half-page scroll, and Ctrl+O should open a functional less-style transcript viewer where j/k/Space/PgUp navigate normally. The [ shortcut should dump the conversation into the terminal's native scrollback buffer.

Steps to Reproduce

Two equivalent reproduction paths, identical outcome:

Path A:

1. claude agents (open Agent View)
2. Create a new session from the Agent View UI
3. Press Enter to attach
4. Generate output longer than the viewport, e.g. ask Claude: 请数 1 到 100，每个数字一行
5. Try Fn+↑ (PgUp) → no effect
6. Try Ctrl+O → transcript opens but j, k, Space, PgUp all do nothing
7. Try [ → typed as literal [ into input box

Path B (same end result):

1. Start a regular claude session
2. Press ← on empty input to navigate into Agent View
3. Re-enter the session
4. Same scroll failure as Path A

Is this a regression?

I don't know — Agent View was introduced in 2.1.139, so this has been broken since the feature shipped (no prior working baseline I can confirm).

Claude Code Version

2.1.143 (Claude Code)

Platform

Anthropic API

Operating System

macOS 26.4.1 (build 25E253)

Terminal/Shell

Other — primary: Ghostty 1.3.1; also reproduced on Warp (see Additional Information)

Additional Information

Cross-terminal repro (rules out terminal-side issue):

• ✅ Reproduces in Ghostty 1.3.1 on macOS 26.4.1
• ✅ Reproduces in Warp (latest) on the same machine

Control — regular claude (no Agent View) works as expected:

• Classic mode + terminal native scrollback functions normally (Cmd+↑/↓, mouse wheel)
• This confirms the issue is specific to Agent View's attached session rendering path, not the terminal or the PgUp key code

Key-code sanity check: Fn+↑ correctly emits ^[[5~ in cat -v outside Claude Code, so the PgUp escape sequence is reaching the application.

Related but distinct issues:

• #59093 — TUI scroll buffer limited to ~10 lines (about buffer size in peek mode, not key responsiveness in attached mode)
• #58925 — stale artifacts on Windows (Windows-specific rendering glitch, now closed)

Workaround: Avoid attaching via Agent View. Use regular claude sessions in separate terminal tabs. Use Agent View only for monitoring/dispatch (never Enter to attach).