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>

docs/adr/0033-halkyon-todo.md

@@ -356,6 +356,37 @@ alternative was put to them, the choice is theirs.
    add.
 4. **Today and Upcoming**, recurrence (D7), reminders on the device.
 5. Todo's first release (0.1.0), its *What's new* drafted by `tool/release.dart`.
+   Decided 2 Nov 2026 (the developer's, the first two the agent's recommendations):
+   - **Deployed beside Learn's server, as Train is** (ADR 0030, D46):
+     `deploy/compose.todo.yaml` at todo.halkyon.eu, a member of Learn's register, its
+     database `halkyon_todo` under a role of its own, taken in by `redeploy.sh` and
+     `backup.sh` where `.env` switches it on, both now going over every app server so
+     switched 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 (agent's choice): a
+     second compose file's default of `INSTANCE_MEMBERS` would have replaced Train's,
+     and Learn's register would no longer have told Train of an account gone.
+     *Alternatives:* the release config alone, Todo's instance later.
+   - **A key of its own** (as Train's D58): a PKCS #12 keystore at
+     `~/.local/share/halkyon-todo/android-release.p12`, alias `halkyon-todo`, in Proton
+     Pass as *Halkyon Todo – Android release keystore*, pinned in
+     `tool/release/todo-android-certificate.sha256` once the developer has made it;
+     until then the release tool releases nothing. *Alternative:* Learn's key, which
+     would let one app's build pass for the other's update.
+   - **The APK, in the F-Droid repository, and a snap** (the developer's, over the APK
+     and F-Droid alone): the listing `app.halkyon.todo.yml` (category *Time*,
+     `NonFreeNet` for the server's SSPL, as Learn's says), the snap `halkyon-todo` to
+     the Store's edge channel, as Learn's, from `apps/todo/snap/`. snapcraft builds one
+     recipe a folder, `snap/snapcraft.yaml`, and the root's is Learn's, so the release
+     tool builds Todo's in a clone of the repository at the tag, kept in
+     `~/.cache/halkyon-release/snap/halkyon-todo` so that its build machine and Flutter
+     part stay from one release to the next, Todo's folder in place of the clone's
+     `snap/` but for `snap/local/`, which the recipes share (agent's choice; over a
+     worktree, whose `.git` file points to a folder LXD doesn't see, and over moving
+     Learn's recipe, which its releases and docs name). The other platforms come
+     later.
+   - Android's backup and transfer to another phone are off, as Train's D53 (agent's
+     choice): the reminders scheduled keep their tasks' titles unsealed on the phone.
 
 ## Consequences