docs: steam-machine-iso: live-session quirks; scripts/qmptype.py types into the VM

.claude/skills/steam-machine-iso/SKILL.md

@@ -125,3 +125,16 @@ unit), through Calamares, then check
 kernel may fail even when DKMS built for the installed kernels. Real
 hardware (Steam Machine, USB stick) is the final test: gamescope, LEDs, CEC,
 power-off.
+
+## Live-session quirks
+
+- Copy/paste doesn't reach QEMU over Moonlight: type commands with
+  `python3 scripts/qmptype.py <vm dir>/qmp.sock "<command>"` (US layout, adds
+  Enter; the VM window's terminal must have focus). QMP `screendump` gives "no
+  surface" with virgl: screenshot the Steam Machine's desktop instead
+  (`spectacle -b -n -f -o /tmp/host.png` in its session).
+- CachyOS Hello refuses to start the installer on a self-built ISO ("testing
+  ISO"): run `calamares-online.sh` in Konsole.
+- `cachyos-calamares-next 3.4.2-13` needs `libboost_*.so.1.91.0` while the
+  repos ship Boost 1.92: steamify-prepare.sh puts 1.91's libraries on the ISO
+  (from archive.archlinux.org) until CachyOS rebuilds it.

scripts/qmptype.py

@@ -0,0 +1,22 @@
+# qmptype.py <qmp socket> <text>: types <text> (US layout) into the VM, then Enter.
+import socket, json, sys, time
+sock, text = sys.argv[1], sys.argv[2]
+s = socket.socket(socket.AF_UNIX); s.connect(sock); f = s.makefile("rw"); f.readline()
+def cmd(c):
+    f.write(json.dumps(c) + "\n"); f.flush(); return f.readline()
+cmd({"execute": "qmp_capabilities"})
+plain = {" ": "spc", "/": "slash", ".": "dot", "-": "minus", "'": "apostrophe", "\n": "ret",
+         "=": "equal", ",": "comma", ";": "semicolon", "\\": "backslash", "[": "bracket_left", "]": "bracket_right"}
+shifted = {"&": "7", "*": "8", "_": "minus", ":": "semicolon", "|": "backslash", "~": "grave_accent",
+           "!": "1", "@": "2", "#": "3", "$": "4", "%": "5", "^": "6", "(": "9", ")": "0", "+": "equal", '"': "apostrophe"}
+for ch in text + "\n":
+    keys = []
+    if ch.isalpha():
+        if ch.isupper(): keys.append("shift")
+        keys.append(ch.lower())
+    elif ch.isdigit(): keys.append(ch)
+    elif ch in plain: keys.append(plain[ch])
+    elif ch in shifted: keys += ["shift", shifted[ch]]
+    else: raise SystemExit("no key for %r" % ch)
+    cmd({"execute": "send-key", "arguments": {"keys": [{"type": "qcode", "data": k} for k in keys]}})
+    time.sleep(0.03)