feat: add system tray and __main__ entry point

Add pystray-based system tray icon with Open UI / Restart / Quit
actions. Add __main__.py for `python -m wled_controller` support.
Update start-hidden.vbs with embedded Python fallback for both
installed and dev environments.

server/scripts/start-hidden.vbs

@@ -0,0 +1,13 @@
+Set fso = CreateObject("Scripting.FileSystemObject")
+Set WshShell = CreateObject("WScript.Shell")
+' Get the directory of this script (scripts\), then go up to app root
+scriptDir = fso.GetParentFolderName(WScript.ScriptFullName)
+appRoot = fso.GetParentFolderName(scriptDir)
+WshShell.CurrentDirectory = appRoot
+' Use embedded Python if present (installed dist), otherwise system Python
+embeddedPython = appRoot & "\python\pythonw.exe"
+If fso.FileExists(embeddedPython) Then
+    WshShell.Run """" & embeddedPython & """ -m wled_controller", 0, False
+Else
+    WshShell.Run "python -m wled_controller", 0, False
+End If