build: the organisation on code.halkyon.app is halkyon-days

ADR 0045, D12, step 1: project-halkyon was renamed halkyon-days, its
repositories keeping their names. Every URL naming it moves along: the
servers' source-code links, which the AGPL requires, and their tests;
the forks in the pubspecs and the lock (appflowy-editor, pure-zstd,
serverpod-offline-sync); the snaps, the F-Droid listings and the
release configurations; the docs. The curator's credit for the
alphabets names the repository by its name since ADR 0015, halkyon,
rather than halkyon_learn. Forgejo redirects the old addresses until
the name is taken again.

ADRs 0015 and 0039 keep the name they were written with, and the local
folders theirs.

halkyon_editor's gen-l10n caches under build/, committed before its
.gitignore named the folder, are no longer tracked.

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/0045-halkyon-days.md

@@ -3,7 +3,8 @@
 - **Status:** decided 12 Nov 2026 by the developer: D1 to D8 and D12 are their own
   choices, D11 too (over the agent's recommendation to keep `halkyon_`), and D16; D9,
   D10, D13 to D15 and D17 the agent's recommendations, which they chose, as the answers
-  to the open questions. Nothing is built yet.
+  to the open questions. Step 1 built 12 Nov 2026: the organisation renamed, every
+  URL naming it changed; the repository is public again since that day.
 - **Builds on:** ADR 0015 (one repository), ADR 0016 (one account across an instance),
   ADR 0017 (a password and an authenticator), ADR 0020 (SimpleLogin), ADR 0031 (the
   apps' icons), ADR 0039 (halkyon.li at home).