space: 32-bit builds — stat fields are int32 there

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

internal/space/walk.go

@@ -90,7 +90,7 @@ func Walk(ctx context.Context, roots []string, progress func(Progress)) (*Node,
 		if err := syscall.Lstat(r, &st); err != nil || st.Mode&syscall.S_IFMT != syscall.S_IFDIR {
 			continue
 		}
-		n := &Node{Name: filepath.Base(r), Dir: true, MTime: st.Mtim.Sec}
+		n := &Node{Name: filepath.Base(r), Dir: true, MTime: int64(st.Mtim.Sec)}
 		if r == "/" {
 			n = root
 		}
@@ -211,7 +211,7 @@ func (w *walker) readDir(j job) {
 		}
 		switch st.Mode & syscall.S_IFMT {
 		case syscall.S_IFDIR:
-			c := &Node{Name: name, Dir: true, MTime: st.Mtim.Sec}
+			c := &Node{Name: name, Dir: true, MTime: int64(st.Mtim.Sec)}
 			j.node.Children = append(j.node.Children, c)
 			if uint64(st.Dev) != j.dev {
 				c.Mount = true // something else is mounted here; if it is this disk's too, it is a root of its own
@@ -219,15 +219,15 @@ func (w *walker) readDir(j job) {
 			}
 			w.push(job{path: p, node: c, dev: j.dev})
 		case syscall.S_IFREG, syscall.S_IFLNK:
-			alloc := st.Blocks * 512
+			alloc := int64(st.Blocks) * 512
 			w.files.Add(1)
 			w.bytes.Add(alloc)
-			if alloc >= KeepMin || st.Size >= KeepMin {
+			if alloc >= KeepMin || int64(st.Size) >= KeepMin {
-				j.node.Children = append(j.node.Children, &Node{Name: name, Size: alloc, Apparent: st.Size, MTime: st.Mtim.Sec})
+				j.node.Children = append(j.node.Children, &Node{Name: name, Size: alloc, Apparent: int64(st.Size), MTime: int64(st.Mtim.Sec)})
 			} else {
 				j.node.SmallN++
 				j.node.SmallSize += alloc
-				j.node.Apparent += st.Size // added to the directory's own apparent total below
+				j.node.Apparent += int64(st.Size) // added to the directory's own apparent total below
 			}
 		}
 	}