fix: v2.5.3 — Windows workspace folders, picker on top, no console flashes

A workspace could not be created on Windows: "cwd must be an absolute path"
for D:\…, because createLane/canonicalCwd tested for a leading "/".

- lanes.js: path.isAbsolute/path.resolve; canonicalCwd stops at any root (a
  missing drive looped forever); resolveLaneByCwd and /ensure accept "\" too
- native-dialog.js: the Windows picker gets an invisible TopMost owner form,
  shown first — an ownerless dialog from the background server opened behind
  the browser, or hidden
- windows-hide.js: every child process on Windows starts with windowsHide,
  required first by the server and the detached scripts (a console window
  flashed per git/npm call)
- Confirm/update/clear-data modals and the quota panel scroll instead of
  overflowing a short window

client/src/components/config/ConfirmDeleteModal.tsx

@@ -67,7 +67,7 @@ export function ConfirmDeleteModal<
         aria-modal="true"
         aria-labelledby="cc-confirm-delete-title"
         aria-describedby="cc-confirm-delete-body"
-        className="relative w-full max-w-lg rounded-xl border border-status-danger/40 bg-surface-1"
+        className="relative flex max-h-full w-full max-w-lg flex-col rounded-xl border border-status-danger/40 bg-surface-1"
         onClick={(e) => e.stopPropagation()}
       >
         <div className="border-b border-border px-4 py-2.5 flex items-center gap-2">
@@ -76,7 +76,7 @@ export function ConfirmDeleteModal<
             {t("edit.confirmDelete")}
           </span>
         </div>
-        <div className="p-4 space-y-3">
+        <div className="min-h-0 overflow-y-auto p-4 space-y-3">
           <p id="cc-confirm-delete-body" className="text-xs text-fg-secondary leading-relaxed">
             {t("edit.confirmDeleteBody")}
           </p>