docs: one repository for every app and shared package (ADR 0015)

The root AGENTS.md holds what applies to every app and package (how
work is done, Serverpod, checks with Melos and the tools, CI); Learn's
own is apps/learn/AGENTS.md, Todo's a note that it is still the
scaffold. The root README introduces the project, Learn's moves to its
folder; LICENSE.md says which licence covers which directory, Todo's
packages unlicensed until decided; one CONTRIBUTING.md. ADR 0015
records the decision; ADR 0014 and 0003 note what moved.

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/0003-card-revisions.md

@@ -32,7 +32,8 @@ conflict: "big" changed to "large" on one device and to "huge" on another become
    conflict, and a side changed differently is a conflict that the app shows with every
    version until the person keeps one. Merging happens when reading; nothing is written
    until the person saves. The code is
-   `halkyon_learn_flutter/lib/src/feature/card/model/card_merge.dart`.
+   `halkyon_learn_flutter/lib/src/feature/card/model/card_merge.dart` (under `apps/learn/`
+   since 2026-10-19, ADR 0015).
    **Amended 2026-10-01, card types:** a card now has a type (front/back, multiple
    choice, vocabulary, matching) and the fields of that type, and the merge runs per
    field instead of per side: the type itself, the front, the back, the answers, the

docs/adr/0014-halkyon-base-module.md

@@ -2,6 +2,11 @@
 
 - **Status:** accepted
 - **Date:** 2026-10-19
+- **Amended by:** [ADR 0015](0015-one-repository.md) (2026-10-19): halkyon_shared's packages
+  now live in this repository's `packages/`, which the apps take by path. Where this record
+  says the module, `halkyon_ui` and `halkyon_app` are pinned by git to signed commits of
+  halkyon_shared's main, read: taken by path, a change to the module and its hosts one
+  commit.
 
 ## Context
 

docs/adr/0015-one-repository.md

@@ -0,0 +1,88 @@
+# ADR 0015: One repository for every app and the packages they share
+
+- **Status:** accepted
+- **Date:** 2026-10-19
+- **Decided by:** the developer, after Melos in each repository was offered instead.
+
+## Context
+
+Until 19 Oct 2026 Halkyon lived in three repositories: Learn's (`halkyon_learn`), the
+shared packages' (`halkyon_shared`: `halkyon_ui`, the `halkyon_base` module of ADR 0014,
+`halkyon_app`, `halkyon_core`, `halkyon_interop`) and Todo's, a local scaffold. Learn took
+the shared packages by git, pinned to signed commits of `halkyon_shared`'s main, as it pins
+the offline sync fork. Every change to a shared package was a round trip: commit there,
+the developer signs and pushes, sends the hash, Learn's pins move, Learn's checks run again.
+On 18 and 19 Oct alone that took four rounds (the theme and widgets, the module,
+`halkyon_app`, data locations as precise as a state), each change only complete across two
+repositories. Todo, Train and Meditate are expected to grow like Learn, slightly smaller,
+on the same shared packages, so the rounds would multiply. Asked whether Melos, which runs
+scripts across a workspace's packages, was worth setting up, the developer chose one
+repository for everything, with Melos on top.
+
+## Decision
+
+1. **One repository, `project-halkyon/halkyon` on code.halkyon.app: Learn's renamed.** It
+   keeps the CI runner's registration, the Actions, the tags and the releases, and Forgejo
+   redirects the old address, so the server's checkout and the F-Droid listing keep
+   working until they are pointed at the new one.
+2. **The layout:** `apps/<app>/` with each app's packages (`apps/learn/`: server, client,
+   app, curator, and `tool/` with the scripts writing Learn's assets; `apps/todo/`),
+   `packages/` with the shared packages, `deploy/` at the root as the instance deploy (other
+   services' compose files are to join Learn's there, which settles how an operator adds a
+   second service), `snap/` at the root (Learn's snap needs the whole workspace to build),
+   `tool/` with the repository's tools, `docs/adr/` with one numbering for every app.
+3. **One pub workspace:** the root `pubspec.yaml` lists every package; one `pubspec.lock`
+   holds one version of each dependency for every app; the apps take the shared packages by
+   path; the root's `dependency_overrides` hold for every app (the sync fork; `cli_util`,
+   below). Todo moved to Serverpod 4.0.4 and Dart 3.13 with the rest.
+4. **History kept, nothing rewritten.** Learn's history is the repository's.
+   `halkyon_shared`'s is merged in as it was, its packages read into `packages/` by the
+   merge itself, so its four commits keep their signatures. Todo's scaffold came in as
+   files: its one commit held the scaffold alone and was unsigned, and the deploy refuses
+   every commit new to it that isn't signed by a key in `deploy/allowed-signers`. Learn
+   moved into `apps/learn/` by a commit of renames alone, so `git log --follow` and blame
+   follow every file.
+5. **Signing** takes one rebase that re-signs only what isn't signed yet:
+   `git rebase -r --exec '[ "$(git log -1 --format=%G?)" = G ] || git commit --amend --no-edit -S' main`.
+   A merged commit whose parents don't change is kept as it is, signature and all; tested
+   in a scratch repository before the move.
+6. **Melos 8.9**, a dev dependency of the root (`dart run melos …`), runs scripts across
+   the packages (`analyze`, `test:dart`, `test:flutter`, `generate`, `check`), each taking
+   Melos' filters (`--diff`, `--include-dependents`, `--scope`).
+7. **Tools in Dart where they hold logic, Bash for glue and for the production host,
+   Python only for Python-only libraries.** `tool/check.dart` replaces `tool/check.sh`
+   (its file selection tested in the root's `test/`), with `--changed-since=<commit>` for
+   only what changed and what depends on it; `tool/pre-push` is the hook (the signature
+   check, then the checks). `deploy/redeploy.sh` and `deploy/backup.sh` stay Bash: the
+   production host has no Dart SDK and gets none. Learn's `tool/release.sh` stays Bash
+   until build 21 is out, so the release that goes with ADR 0014's breaking deploy uses the
+   script it was proven with; then a release tool in Dart, shared by the apps and tagging
+   per app (`learn-vX.Y.Z`), takes over.
+8. **The move happens while deploys pause** (until 22 Oct, after the hackathon's judging):
+   the first deploy from the new layout comes with build 21.
+
+## Consequences
+
+- A change to a shared package and to every app using it is one commit, checked as one;
+  a shared package's change must keep every app's tests passing in the same commit.
+- One version of each dependency across the apps: an app's upgrade moves every app.
+  Serverpod moves as one already (ADR 0014). Melos needs `cli_util` 0.5, which Learn's
+  `flutter_launcher_icons` (0.14.4, its latest) doesn't allow; the root overrides it to
+  0.5.2, as that package uses only `cli_util`'s logger, unchanged in 0.5. Drop the override
+  once it allows 0.5.
+- CI checks every package on every push, and the generated-code check covers every
+  server package (`dart run melos run generate`); the four throwaway test passwords CI
+  gives cover the module's and Todo's server tests too.
+- **Deploys:** `deploy/` stays at the root, so the command the runner's key is pinned to on
+  learn.halkyon.eu's server (`/home/deploy/halkyon-learn/deploy/redeploy.sh`) is unchanged,
+  and the server's checkout keeps its folder. Its images are built from the root with the
+  workspace narrowed to what they need (`tool/workspace_only.sh`: Learn's server and the
+  module; the curator), checked by building both images before the move. The first deploy
+  after the move starts the server once more than needed, as the deployed copy of
+  `redeploy.sh` looks for migrations at their old path.
+- `halkyon_shared`'s repository is archived, not deleted: Learn's commits before the move
+  pin it. Its commit style gives way to the repository's typed commits.
+- Todo's packages have no licence until the developer decides (`LICENSE.md`).
+- References to the old repository address in code and listings (the source link Learn's
+  instances name, the snap's and the F-Droid listing's source, the curator's credits) work
+  through Forgejo's redirect until they are changed to `project-halkyon/halkyon`.