A selection holds up to 1024 ranges on the desktop, 64 on the board

The limit was 64 everywhere, which helix-golf's enumerate_and_align outgrows
(%s |\d+ makes 121 ranges). It is now memory.limits.selections, per platform,
and the counts that hold it are u16. The ranges stay inline in each Text, so a
pane grows by about 80 KiB on the desktop (three texts and the regex prompt's
snapshot); the Pane size budget in Terminal.zig moves from 128 to 160 KiB and
says why.

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

1 files changed, 3 insertions, 2 deletions

diff --git a/src/Text.zig b/src/Text.zig
index 764b8a6a..56ee199b 100644
--- a/src/Text.zig
+++ b/src/Text.zig
@@ -11,6 +11,7 @@ const std = @import("std");
 const panes = @import("panes.zig");
 const modal = @import("modal.zig");
 const config = @import("config.zig");
+const memory = @import("memory.zig");
 const Pane = panes.Pane;
 const File = panes.File;
 const Terminal = panes.Terminal;
@@ -36,7 +37,7 @@ pub const CharSel = struct {
     explicit: bool = false,
 };
 
-pub const max_selections = 64;
+pub const max_selections = memory.limits.selections;
 
 pub const SelRange = struct {
     row: i32,
@@ -60,7 +61,7 @@ cur_col: i32 = 0,
 msel: LineSel = .{},
 vsel: CharSel = .{},
 sels: [max_selections - 1]SelRange = undefined,
-nsel: u8 = 0,
+nsel: u16 = 0,
 select: bool = false,
 /// sticky goal column for j/k runs (helix old_visual_position): any
 /// non-vertical range write resets it to -1.