Move the mouse out of pardes.zig into mouse.zig

Pure move, no behaviour change: handleMouse with dragUpdate, dragRelease,
seamIdxAt, reportGesture, gestureRange, dispatchPointerBuiltin,
mirrorTtySelection and chordCutPaste, the pointer hit helpers
(bodyHitForPane, sameTagCell, tagColumn, sameBodyCell), chromeTarget with
ChromeTarget, paneAt, the Drag state type with clampBorderCol/Row, the seam
test fixtures and thirteen pointer and drag tests go verbatim to mouse.zig.

The methods become free functions taking `p: *Pardes`; their 36 call sites
change from `p.handleMouse(..)` to `mouse.handleMouse(p, ..)`, including
web.zig's chromeTarget and macos.zig's paneAt. The Mouse event type stays
in pardes.zig with the rest of the event vocabulary.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

1 files changed, 2 insertions, 1 deletions

diff --git a/src/macos.zig b/src/macos.zig
index cab8212a..f83fb8b4 100644
--- a/src/macos.zig
+++ b/src/macos.zig
@@ -6,6 +6,7 @@ const builtin = @import("builtin");
 const posix = std.posix;
 const libc = std.c;
 const pardes = @import("pardes.zig");
+const mouse = @import("mouse.zig");
 const colors = @import("colors.zig");
 const look = @import("look.zig");
 const message = pardes.Messages.Message;
@@ -2623,7 +2624,7 @@ const Spent = struct {
 };
 
 fn spendScroll(st: *State, delta_rows: f32, delta_cols: f32, col: u16, row: u16) Spent {
-    const pane = if (st.core.paneAt(col, row)) |id| st.core.panes[id] else null;
+    const pane = if (mouse.paneAt(st.core, col, row)) |id| st.core.panes[id] else null;
     var out: Spent = .{};
     var down_left = takeScrollTicks(&st.scroll_lag, delta_rows);
     while (down_left != 0) {