janus: Allow app to be installed from Debian unstable

- Janus is currently not installable in Trixie because Janus was temporarily
removed during the release process of Trixie.

- Installing it from unstable, despite the instability is better than keeping
the app unavailable. Users have reported using the app.

Tests:

- Restarting the service after applying the patch leads to setup for upgrades
app to run. Apt preferences for janus packages are set. App is shown as
available. It can be installed.

Signed-off-by: Sunil Mohan Adapa <sunil@medhas.org>
Reviewed-by: James Valleroy <jvalleroy@mailbox.org>

plinth/modules/janus/__init__.py

@@ -25,6 +25,11 @@ _description = [
     format_lazy(
         _('<a href="{coturn_url}">Coturn</a> is required to '
           'use Janus.'), coturn_url=reverse_lazy('coturn:index')),
+    format_lazy(
+        _('<strong>Note:</strong> This app receives frequent feature updates. '
+          'It can only be installed if frequent feature updates is enabled in '
+          'the <a href="{upgrades_url}">Software Update</a> app.'),
+        upgrades_url=reverse_lazy('upgrades:index')),
 ]
 
 

plinth/modules/upgrades/__init__.py

@@ -55,7 +55,7 @@ class UpgradesApp(app_module.App):
 
     app_id = 'upgrades'
 
-    _version = 20
+    _version = 21
 
     can_be_disabled = False
 

plinth/modules/upgrades/privileged.py

@@ -74,6 +74,17 @@ Explanation: matrix-synapse recommends python3-pympler
 Package: python3-pympler
 Pin: release n=sid
 Pin-Priority: 200
+
+Explanation: Make janus package and its dependencies installable from Debian
+Explanation: 'unstable' distribution.
+Package: janus
+Pin: release n=sid
+Pin-Priority: 200
+
+Explanation: Janus app in FreedomBox needs the package for web UI.
+Package: libjs-janus-gateway
+Pin: release n=sid
+Pin-Priority: 200
 '''
 
 APT_PREFERENCES_UNSTABLE = \