M0 scaffold — Python addon + Rust sidecar

Kodi addon (plugin.video.torttube) shell with Cargo workspace for the
rustypipe-backed sidecar binary. No working extraction yet — addon.xml
parses, main.py is a notification stub, sidecar's main.rs prints scaffold
banner. See MILESTONES.md for M1..M6.

License: GPL-3.0-or-later (matches rustypipe + NewPipeExtractor).

addon/plugin.video.torttube/main.py

@@ -0,0 +1,24 @@
+# torttube — Kodi YouTube addon
+# SPDX-License-Identifier: GPL-3.0-or-later
+"""M0 scaffold entry point. Sidecar handoff lands in M1+."""
+
+import sys
+
+import xbmcgui
+import xbmcplugin
+
+_HANDLE = int(sys.argv[1]) if len(sys.argv) > 1 else -1
+
+
+def main() -> None:
+    xbmcgui.Dialog().notification(
+        "torttube",
+        "M0 scaffold — playback wires up in M3",
+        xbmcgui.NOTIFICATION_INFO,
+        2500,
+    )
+    xbmcplugin.endOfDirectory(_HANDLE)
+
+
+if __name__ == "__main__":
+    main()