fix: v2.5.8 — the browser terminal attaches on Windows

node-pty on Windows looks the file it starts up on PATH exactly as given and
never adds `.exe`, so `tmux attach-session` started as a bare `tmux` failed
with "File not found" on every attach: the browser's terminal socket opened,
closed, and reconnected every 1.5 s.

- pty-attach.js: attachBinary names tmux by its full file name on Windows
  (ai-tools.which("tmux"), else tmux.exe)
- websocket.js: an attach that throws is logged as `[WS] attach <run> failed`,
  the one place that says why the terminal keeps reconnecting

openapi.yaml

@@ -3,7 +3,7 @@
 openapi: 3.0.3
 info:
   title: Agent Dashboard for Claude Code API
-  version: 2.5.7
+  version: 2.5.8
   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