build(todo): Todo deployable beside Learn's server, and released as an APK, on F-Droid and as a snap (ADR 0033, step 5)

deploy/compose.todo.yaml adds Todo's server at todo.halkyon.eu, a member
of Learn's register, its database halkyon_todo in the instance's
PostgreSQL, its image built as Train's. redeploy.sh and backup.sh go over
every app server .env switches on (train, todo). Each compose file names
its server to the register in a variable of its own
(INSTANCE_MEMBER_TRAIN, INSTANCE_MEMBER_TODO), which halkyon_base adds to
INSTANCE_MEMBERS, each address once, as a second compose file's default
would have replaced Train's.

apps/todo/release.dart configures the release tool for Todo's APK and
snap: a key of its own (pinned once made; until then nothing is
released), the F-Droid listing (Time, NonFreeNet), and the snap from
apps/todo/snap/, which the tool builds in a clone of the repository at the
tag with that folder in place of snap/, as snapcraft builds one recipe a
folder and the root's is Learn's. What's new for 0.1.0 in English and
German, now shown. Android's backup and transfer are off, as Train's
(D53): the reminders scheduled keep their tasks' titles unsealed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

tool/release/fdroid/config/categories.yml

@@ -3,3 +3,5 @@ Education:
   name: Education
 Sports & Health:
   name: Sports & Health
+Time:
+  name: Time

tool/release/fdroid/metadata/app.halkyon.todo.yml

@@ -0,0 +1,36 @@
+# Halkyon Todo's listing in the F-Droid repository: the snap's summary and description
+# (apps/todo/snap/snapcraft.yaml), and its anti-feature with its reason (ADR 0033,
+# step 5).
+Categories:
+  - Time
+License: AGPL-3.0-or-later
+AuthorName: Halkyon
+AuthorEmail: support@halkyon.app
+WebSite: https://halkyon.app/todo
+SourceCode: https://code.halkyon.app/project-halkyon/halkyon
+
+AntiFeatures:
+  NonFreeNet: The server's licence (SSPL) isn't a free licence by F-Droid's
+    definition.
+
+Name: Halkyon Todo
+Summary: Tasks and projects, sealed and synced between your devices
+Description: |-
+  Halkyon Todo keeps your tasks: an Inbox for what comes up, projects with
+  sections, sub-tasks and labels, Today with what is overdue, and Upcoming as
+  an agenda that opens into the month. Tasks repeat (every day, every other
+  Tuesday, the first Monday of each month), have reminders, deadlines and
+  priorities, and are typed the quick way: "Call Anna tomorrow 9am #Home p1".
+
+  Each project shows as a list, a board or a calendar, grouped, sorted and
+  filtered as you set it, the same on every device. Tasks are dragged between
+  sections, days and hours.
+
+  Everything is sealed on your device with your account's keys before it
+  reaches the instance, which can't read it. You sign in with SimpleLogin, by
+  Proton, or with an email address, a password and an authenticator app. It
+  connects to todo.halkyon.eu, the project's instance, or to any other:
+  everything an instance needs is in the repository, to run your own. The app
+  is AGPL-3.0 and the server SSPL-1.0, so all of its code is public.
+
+  Questions and reports: support@halkyon.app

tool/release/todo-android-certificate.sha256

@@ -0,0 +1,3 @@
+# The SHA-256 of the certificate that signs Halkyon Todo's Android releases (key alias
+# halkyon-todo), as keytool prints it. tool/release.dart releases no APK signed otherwise,
+# and none at all until the key is made and its SHA-256 written below.