release: the Plasma classroom becomes stable 0.2.0

0.1.50 was taken to the church and the things a container cannot answer
were answered on the hardware: boot, autologin, the panel after a reboot,
panel and browser scaling, Wonder Ink, Parent Call opening in the corner
and reaching the sanctuary with a typed name, readable and silent
notifications, HDMI audio and the volume keys.

The promotion is a fast-forward. The experiment was cut from the
published stable source and never diverged from it, so master reaches
this work without a merge and there is one history.

One thing changed for the release. The channel rules turn around:
classroom-v2 and hyprland are the obsolete channels now and a room on
either comes home to stable, while canary — where the next development
release goes — and any channel somebody named by hand stay where they
were put. A fresh installation has always defaulted to stable.

Nothing else moved. This is the 0.1.50 that was verified, with a version
number and a channel rule.

Co-Authored-By: Claude Opus 5 <[email protected]>

scripts/classroom-migrate

@@ -189,13 +189,19 @@ import re
 import sys
 
 OBSOLETE_KEYS = ("COMPOSITOR", "HYPR_APPEARANCE")
-# Every channel that serves a desktop this package replaces. A machine
-# that has just installed the Plasma classroom must not be left pointed at
-# a line that will hand it the sway build back at the next release: stable
-# and canary both would. A room already on the v2 channel, or on one
-# somebody named deliberately, is left where it is.
-OBSOLETE_CHANNELS = {"stable", "canary", "hyprland"}
-CHANNEL = "classroom-v2"
+# Every channel that serves a desktop this package replaces.
+#
+# This list was the other way round while the Plasma desktop was an
+# experiment: rooms were moved off stable onto a channel of its own so
+# that a sway release could not take them back. The Plasma classroom is
+# the stable one now, so the experiment's channel is the obsolete one and
+# rooms come home. hyprland never carried anything anybody runs.
+#
+# canary is deliberately not here. It is the next development release's
+# channel, and a room an administrator put there is a room somebody meant
+# to put there — as is one on a channel named by hand.
+OBSOLETE_CHANNELS = {"classroom-v2", "hyprland"}
+CHANNEL = "stable"
 
 # The church broker. One address for every room.
 BROKER_HOST = "10.40.0.2"