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/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`: