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/StatusBar.tsx

@@ -208,7 +208,7 @@ function QuotaPanel({
       onMouseLeave={onLeave}
       onFocus={onEnter}
       onBlur={onLeave}
-      className="fixed bottom-7 right-2 z-[9999] w-[19rem] max-w-[calc(100vw-1rem)] rounded-lg border border-border bg-surface-2 px-3 py-2.5 text-[11px] leading-snug text-fg-primary shadow-lg shadow-black/20"
+      className="fixed bottom-7 right-2 z-[9999] max-h-[calc(100vh-2.5rem)] w-[19rem] max-w-[calc(100vw-1rem)] overflow-y-auto rounded-lg border border-border bg-surface-2 px-3 py-2.5 text-[11px] leading-snug text-fg-primary shadow-lg shadow-black/20"
     >
       <div className="mb-2 font-semibold">{t("statusBar.quotaTitle")}</div>
       {groups.map(([id, list]) => (