docs: document terminal-specific fullscreen mouse behavior (#7965)

* docs(coding-agent): document iTerm2 fullscreen scroll workaround

* docs(coding-agent): document Ghostty fullscreen link behavior

packages/coding-agent/docs/keybindings.md

@@ -86,7 +86,7 @@ The dedicated history actions always change history entries, regardless of the c
 
 ### TUI Fullscreen Viewport
 
-These actions apply when interactive mode uses `--tui-mode fullscreen` and target the primary transcript scroll region. Two-finger trackpad and mouse-wheel input scroll the region under the pointer, falling back to the transcript over the fixed editor/status/footer dock. Clicking an OSC 8 hyperlink opens it in the default handler. Dragging with the primary mouse button selects text and copies it to the clipboard; holding at the transcript's top or bottom edge auto-scrolls into off-screen content.
+These actions apply when interactive mode uses `--tui-mode fullscreen` and target the primary transcript scroll region. Two-finger trackpad and mouse-wheel input scroll the region under the pointer, falling back to the transcript over the fixed editor/status/footer dock. Clicking an OSC 8 hyperlink opens it in the default handler. Dragging with the primary mouse button selects text and copies it to the clipboard; holding at the transcript's top or bottom edge auto-scrolls into off-screen content. See [Terminal setup](terminal-setup.md) for terminal-specific mouse and trackpad behavior.
 
 Fullscreen transcript bindings take precedence over editor bindings. The default unmodified navigation keys therefore control the transcript in fullscreen mode, while their `ctrl` variants continue to control the editor. Outside fullscreen mode, both variants control the editor.
 

packages/coding-agent/docs/terminal-setup.md

@@ -2,9 +2,26 @@
 
 Pi uses the [Kitty keyboard protocol](https://sw.kovidgoyal.net/kitty/keyboard-protocol/) for reliable modifier key detection. Most modern terminals support this protocol, but some require configuration.
 
-## Kitty, iTerm2
+## Kitty
 
-Work out of the box.
+Works out of the box.
+
+## iTerm2
+
+### Regular TUI mode
+
+Works out of the box.
+
+### Fullscreen TUI mode
+
+Pi owns the viewport, so iTerm2 sends mouse-wheel reports instead of scrolling its native scrollback. With iTerm2's default fast-trackpad behavior, those reports can lose most of an accelerated wheel delta, making fullscreen scrolling much slower than regular scrolling.
+
+If fast mouse-wheel gestures move only about one line at a time in fullscreen mode:
+
+1. Open **iTerm2 → Settings → Advanced**.
+2. Search for **Trackpad scrolls fast?** and set it to **No**.
+
+This is an iTerm2-wide workaround and may also change native trackpad scrolling. The underlying behavior is tracked in [iTerm2 issue 9619](https://gitlab.com/gnachman/iterm2/-/work_items/9619).
 
 ## Apple Terminal
 
@@ -32,6 +49,10 @@ If Claude Code 2.x or newer is the only reason you added that mapping, you can r
 
 Pi binds `Ctrl+J` as a default newline alias, so `Shift+Enter` keeps working in tmux via that remap without extra pi configuration.
 
+### Fullscreen TUI mode
+
+In fullscreen mode, links remain clickable, but Ghostty does not show its hover underline or lower-left URL preview while pi captures mouse input. Hold `Shift+Command` on macOS or `Shift+Ctrl` on Linux to use Ghostty's native link handling.
+
 ## WezTerm
 
 WezTerm usually works out of the box for `Shift+Enter` via xterm modifyOtherKeys. To use the Kitty keyboard protocol explicitly, create `~/.wezterm.lua`:

packages/coding-agent/docs/usage.md

@@ -248,7 +248,7 @@ pi --no-extensions -e ./my-extension.ts
 | `-h`, `--help` | Show help |
 | `-v`, `--version` | Show version |
 
-In `fullscreen` mode, the transcript scrolls inside the terminal viewport while queued messages, working status, extension widgets, editor, and footer remain fixed at the bottom. Mouse/trackpad input scrolls the region under the pointer; keyboard viewport actions always remain available. Inline images work in terminals that support the Kitty graphics protocol, including Kitty and Ghostty. In iTerm2 they render as text placeholders because its inline-image protocol cannot delete or crop placements during application-owned scrolling. In `regular` mode, pi uses the main screen and terminal-owned scrollback, and iTerm2 inline images continue to render normally.
+In `fullscreen` mode, the transcript scrolls inside the terminal viewport while queued messages, working status, extension widgets, editor, and footer remain fixed at the bottom. Mouse/trackpad input scrolls the region under the pointer; keyboard viewport actions always remain available. Inline images work in terminals that support the Kitty graphics protocol, including Kitty and Ghostty. In iTerm2 they render as text placeholders because its inline-image protocol cannot delete or crop placements during application-owned scrolling. In `regular` mode, pi uses the main screen and terminal-owned scrollback, and iTerm2 inline images continue to render normally. See [Terminal setup](terminal-setup.md) for terminal-specific settings and workarounds.
 
 Set **TUI mode** in `/settings` to switch between `regular` and `fullscreen` immediately and choose the default for future sessions. **Fullscreen exit output** controls whether exiting fullscreen prints the final transcript or restores the previous screen and prints only the session resume hint.