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

openapi.yaml

@@ -3,7 +3,7 @@
 openapi: 3.0.3
 info:
   title: Agent Dashboard for Claude Code API
-  version: 2.5.2
+  version: 2.5.3
   description: HTTP API for real-time Claude Code session monitoring, agent lifecycle tracking, analytics, pricing, hooks ingestion, and workflow intelligence.
   contact:
     name: Nguyễn Ngọc Trí Vĩ