feat: give the classroom a desktop instead of a shell

The whole appliance UI is now configuration for a desktop Debian already ships: a Plasma 6.3 session with a colour scheme, a look and feel package that builds the bar, window rules, and KDE's own Kiosk restrictions. Two things were measured rather than assumed, and both changed a decision. Plasma restarts a crashed panel three times a minute and then gives up, which is the failure a classroom has already had. Four lines of systemd drop-in make it unconditional; the panel then survived eight SIGKILLs a second apart, back each time in 2.4s. Plasma draws a minimised task and a background task identically, so the five states the room needs cannot all be shown. Rather than write a task manager, the classroom removes minimise: clicking a launcher always means show me this. Co-Authored-By: Claude Opus 5 <[email protected]>
2026-09-10 08:35:12 -05:00
parent bfc7caf28f
commit 87b55761c6
51 changed files with 1352 additions and 36 deletions
@@ -0,0 +1,60 @@
+# Ekklesia Classroom session policy.
+#
+# Installed to /etc/xdg/kdeglobals, where it is the bottom of Plasma's
+# configuration cascade. Every group is marked [$i] — immutable — so a
+# teacher, a stray click or a misbehaving application cannot override it
+# from the user's own configuration. This is KDE's own Kiosk mechanism:
+# nothing here is achieved by deleting a binary or hiding a menu entry.
+#
+# Lifting a restriction for maintenance is a one-line edit to this file
+# followed by a session restart, which is what makes the appliance
+# serviceable rather than merely locked.
+
+[KDE Action Restrictions][$i]
+# No way to reach a shell, a command line, or an arbitrary program.
+action/kdesktop_rmb=false
+action/kwin_rmb=false
+action/openwith=false
+action/switch_user=false
+action/start_new_session=false
+action/lock_screen=false
+run_command=false
+shell_access=false
+logout=false
+# The desktop and the panel are a fixed part of the appliance.
+editable_desktop_icons=false
+editable_bookmarks=false
+movable_toolbars=false
+plasma/plasmashell/unlockedDesktop=false
+plasma-desktop/scripting_console=false
+# Nothing in the classroom should offer to file a bug or open a manual.
+action/help_report_bug=false
+action/help_about_kde=false
+action/help_contents=false
+
+[General][$i]
+ColorScheme=EkklesiaDark
+AccentColor=79,179,168
+# The teacher's own words are not decoration: keep text rendering plain
+# and readable rather than styled.
+XftAntialias=true
+XftHintStyle=hintslight
+XftSubPixel=rgb
+
+[KDE][$i]
+widgetStyle=Breeze
+LookAndFeelPackage=org.ekklesia.classroom.desktop
+SingleClick=false
+AnimationDurationFactor=0.5
+
+[Icons][$i]
+Theme=breeze-dark
+
+[KFileDialog Settings][$i]
+Allow Expansion=false
+Automatically select filename extension=true
+Show Bookmarks=false
+Show Full Path=false
+Show Inline Previews=false
+Show Speedbar=false
+Sort directories first=true