Add native Windows host daemon (bleak/WinRT)

Adds a Windows port of the host daemon so the Clawdmeter stays connected
on Windows independent of WSL. Mirrors the macOS daemon and speaks the
existing GATT data service unchanged — no firmware changes.

- claude_usage_daemon_windows.py: Windows-local OAuth token read +
  Anthropic poll + BLE scan/connect/write, with auto-reconnect
  (connect-retry wrapper, zombie-link break, split fast/slow backoff)
- tray_windows.py: pystray login-startup tray app (status icon + Quit)
- autostart_windows.py: winreg HKCU\Run autostart via pythonw.exe
- icon_assets.py: per-state tray icons composited from logo.h
- install-windows.ps1 + daemon/README-windows.md: turnkey setup
- pytest suite: token / poll / reconnect / tray / autostart / no-WSL guard

daemon/requirements-windows.txt

@@ -0,0 +1,6 @@
+# Windows-only dependency manifest for claude_usage_daemon_windows.py
+# The macOS/Linux daemons manage their own dependencies separately.
+bleak
+httpx
+pystray
+Pillow