…d-industries#49931)

Follow-up to zed-industries#45600.

## Summary

Fix mouse scroll reports sending only one event when scrolling down in
terminal apps with mouse mode (tmux, neovim, etc.), regardless of how
many lines were scrolled.

## The Problem

After zed-industries#45600, trackpad scrolling speed was fixed. But when scrolling
**down** (negative `scroll_lines`), the terminal was still sending only
**one** scroll report per gesture, no matter how many lines the user
scrolled. Scrolling up worked correctly.

## Root Cause

In `scroll_report()` we had:

https://github.com/zed-industries/zed/blob/a8043dcff8f28a0443d7ec238e7f020689ebe1ff/crates/terminal/src/mappings/mouse.rs#L96

`scroll_lines` can be negative (scroll down) or positive (scroll up).
For negative values:

| scroll_lines | max(scroll_lines, 1) | Reports sent | Verdict |
|--------------|---------------------|--------------|------|
| 3 (up)       | 3                   | 3           |Right
| -3 (down)    | 1                   | 1           |WRONG|

So we always sent exactly 1 report when scrolling down, losing the
scroll magnitude.

Use `scroll_lines.unsigned_abs()` instead of `max(scroll_lines, 1)`.
This matches how `alt_scroll()` in the same file already handles
`scroll_lines`. Now both directions send the correct number of reports.

https://github.com/zed-industries/zed/blob/a8043dcff8f28a0443d7ec238e7f020689ebe1ff/crates/terminal/src/mappings/mouse.rs#L102

## Testing

- Added unit tests: `scroll_report_repeats_for_negative_scroll_lines`
and `scroll_report_repeats_for_positive_scroll_lines`
- Manually tested scrolling in tmux and neovim with mouse mode

---

Release Notes:

- Fixed mouse scroll in terminal apps (tmux, neovim, etc.) only sending
one scroll event when scrolling down, regardless of scroll amount

…d-industries#49931)

Follow-up to zed-industries#45600.

## Summary

Fix mouse scroll reports sending only one event when scrolling down in
terminal apps with mouse mode (tmux, neovim, etc.), regardless of how
many lines were scrolled.

## The Problem

After zed-industries#45600, trackpad scrolling speed was fixed. But when scrolling
**down** (negative `scroll_lines`), the terminal was still sending only
**one** scroll report per gesture, no matter how many lines the user
scrolled. Scrolling up worked correctly.

## Root Cause

In `scroll_report()` we had:

https://github.com/zed-industries/zed/blob/a8043dcff8f28a0443d7ec238e7f020689ebe1ff/crates/terminal/src/mappings/mouse.rs#L96

`scroll_lines` can be negative (scroll down) or positive (scroll up).
For negative values:

| scroll_lines | max(scroll_lines, 1) | Reports sent | Verdict |
|--------------|---------------------|--------------|------|
| 3 (up)       | 3                   | 3           |Right
| -3 (down)    | 1                   | 1           |WRONG|

So we always sent exactly 1 report when scrolling down, losing the
scroll magnitude.

Use `scroll_lines.unsigned_abs()` instead of `max(scroll_lines, 1)`.
This matches how `alt_scroll()` in the same file already handles
`scroll_lines`. Now both directions send the correct number of reports.

https://github.com/zed-industries/zed/blob/a8043dcff8f28a0443d7ec238e7f020689ebe1ff/crates/terminal/src/mappings/mouse.rs#L102

## Testing

- Added unit tests: `scroll_report_repeats_for_negative_scroll_lines`
and `scroll_report_repeats_for_positive_scroll_lines`
- Manually tested scrolling in tmux and neovim with mouse mode

---

Release Notes:

- Fixed mouse scroll in terminal apps (tmux, neovim, etc.) only sending
one scroll event when scrolling down, regardless of scroll amount

…d-industries#49931)

Follow-up to zed-industries#45600.

## Summary

Fix mouse scroll reports sending only one event when scrolling down in
terminal apps with mouse mode (tmux, neovim, etc.), regardless of how
many lines were scrolled.

## The Problem

After zed-industries#45600, trackpad scrolling speed was fixed. But when scrolling
**down** (negative `scroll_lines`), the terminal was still sending only
**one** scroll report per gesture, no matter how many lines the user
scrolled. Scrolling up worked correctly.

## Root Cause

In `scroll_report()` we had:

https://github.com/zed-industries/zed/blob/a8043dcff8f28a0443d7ec238e7f020689ebe1ff/crates/terminal/src/mappings/mouse.rs#L96

`scroll_lines` can be negative (scroll down) or positive (scroll up).
For negative values:

| scroll_lines | max(scroll_lines, 1) | Reports sent | Verdict |
|--------------|---------------------|--------------|------|
| 3 (up)       | 3                   | 3           |Right
| -3 (down)    | 1                   | 1           |WRONG|

So we always sent exactly 1 report when scrolling down, losing the
scroll magnitude.

Use `scroll_lines.unsigned_abs()` instead of `max(scroll_lines, 1)`.
This matches how `alt_scroll()` in the same file already handles
`scroll_lines`. Now both directions send the correct number of reports.

https://github.com/zed-industries/zed/blob/a8043dcff8f28a0443d7ec238e7f020689ebe1ff/crates/terminal/src/mappings/mouse.rs#L102

## Testing

- Added unit tests: `scroll_report_repeats_for_negative_scroll_lines`
and `scroll_report_repeats_for_positive_scroll_lines`
- Manually tested scrolling in tmux and neovim with mouse mode

---

Release Notes:

- Fixed mouse scroll in terminal apps (tmux, neovim, etc.) only sending
one scroll event when scrolling down, regardless of scroll amount