show progress for imports and deletions

development.md

@@ -20,6 +20,8 @@ src/               main process (Node/Electron backend)
   prefixes.js      prefix registry (files/wineprefixes)
   symlinks.js      relative symlink rewiring + executable-bit restoration
                    (shared by imports, prefixes and LAN sync)
+  fsutil.js        tree copy/remove with byte progress + rate-gated progress
+                   events (imports, prefix/wine/app deletion, LAN sync)
   importer.js      app import (copy/move/leave/prefix)
   names.js         user-typed name sanitizing (prefix folder names, wine
                    display names)
@@ -73,6 +75,11 @@ handlers in src/ipc/. Keep new APIs in that pattern.
   next to the handlers in src/ipc/, use the games service's running list plus
   the helpers in library.js (prefixNameForGame/gamesUsingPrefix/is*InUse) and
   answer { ok:false, error:'inUse'|'hasApps', apps:[names] } for the toast.
+- Long operations stream progress through the single import:progress slot as
+  { phase: 'count'|'copy'|'remove', files, bytes, totalFiles, totalBytes } and
+  the renderer drives a bar from it (runWithProgress for deletes/imports).
+  Emit the 'count' phase first (a treeSize walk) and copy/remove through the
+  fsutil helpers; never ship a progress bar no data can move.
 - CSS: reuse the existing variables/classes (.button, .field-label,
   .custom-select, form-card); spacing rhythm comes from --button-margin and
   the flex gap of the container, not per-element magic numbers.