Closes#18930
### Summary
- Fix fast Macbook trackpad/mouse scrolling in terminal applications
with mouse mode enabled
### The Problem
Scrolling with a trackpad in tmux, neovim, or any terminal app that
enables mouse mode was too fast. A gentle swipe would send me through
hundreds of lines, making these apps practically unusable in Zed's
terminal.
### Root Cause
When the terminal is in mouse mode, we send escape sequences to report
scroll events to the application. The bug was in `scroll_report()`:
ca47822667/crates/terminal/src/terminal.rs (L1983-L1988)
That `max(scroll_lines, 1)` meant we'd send **at least 1 scroll event
even when `scroll_lines` was 0**.
ca47822667/crates/terminal/src/mappings/mouse.rs (L96)
On macOS, trackpad gestures fire many small pixel deltas due to scroll
acceleration. Each tiny movement triggered a scroll event, even though
we hadn't accumulated enough pixels for a full line yet. This is a known
issue alacritty/alacritty#2869 - macOS sends fractional line deltas
(like 0.1) instead of whole lines.
### The Fix
Don't send mouse reports when no full line has accumulated
This aligns with Alacritty's approach - accumulate partial scroll
amounts and only report when complete lines are ready.
6ee6e53ee3/alacritty/src/input/mod.rs (L700-L730)
### Testing
Tested trackpad scrolling in:
- tmux (pane navigation, scrollback)
- neovim (buffer scrolling)
- opencode (TUI navigation)
All scroll smoothly now.
### Demo
The demo shows the behavior of the scrolling. I can go fast or I can go
slow
https://github.com/user-attachments/assets/14bfc2f4-f286-4341-bf55-4ced894d63f9
Release Notes:
- Fixed trackpad scrolling being too fast in terminal applications with
mouse mode enabled (tmux, neovim, opencode, etc.)
6c712d88e4