Fix review findings and Windows setup issues found in testing

- Run the server with -X utf8: the bundled Windows Python ignores PYTHON* variables.
- Quote every argument in Windows terminal commands, so cmd metacharacters are literal.
- frame_connect: accept HOST:PORT, validate input, retry the config swap while
  Windows' ssh.exe holds ~/.ssh/config locked, and don't apply 0o700 on Windows.
- Never use rsync on Windows; unbounded stream queue; validate FRAME_ALIAS;
  more Linux terminals; bundle the window icon; docs and wording fixes.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

ui/frame_host.py

@@ -146,16 +146,18 @@ def open_terminal(argv, title="Frame Control"):
         # `start` gives the command its own console window; cmd /k keeps it open.
         # One hand-built command line: quoting it twice through list2cmdline would
         # produce backslash-escaped quotes, which cmd doesn't understand.
-        inner = subprocess.list2cmdline(argv)
+        # Every argument is quoted, so cmd treats & | < > ^ in them literally.
+        inner = " ".join('"%s"' % a.replace('"', '\\"') for a in argv)
         subprocess.Popen(f'cmd.exe /c start "{title}" cmd.exe /k "{inner}"', **DETACHED)
         return "a terminal window"
     script = f'{shlex.join(argv)}; echo; read -r -p "Press Enter to close. " _'
-    for name, flag in (("x-terminal-emulator", "-e"), ("gnome-terminal", "--"), ("konsole", "-e"),
-                       ("xfce4-terminal", "-x"), ("kitty", None), ("alacritty", "-e"),
-                       ("foot", None), ("xterm", "-e")):
+    for name, flags in (("x-terminal-emulator", ["-e"]), ("gnome-terminal", ["--"]), ("ptyxis", ["--"]),
+                        ("kgx", ["--"]), ("konsole", ["-e"]), ("xfce4-terminal", ["-x"]),
+                        ("tilix", ["-e"]), ("lxterminal", ["-e"]), ("kitty", []), ("alacritty", ["-e"]),
+                        ("wezterm", ["start", "--"]), ("foot", []), ("xterm", ["-e"])):
         exe = which(name)
         if exe:
-            _spawn([exe, *([flag] if flag else []), "bash", "-c", script])
+            _spawn([exe, *flags, "bash", "-c", script])
             return name
     raise HostError("No terminal program found (tried gnome-terminal, konsole, xterm and others)")