recipe-maintainer: public snapshot (secrets + deployment plans removed, single commit)

Sanitized single-commit public mirror of recipe-maintainer.
- Removed test-ssh/.testenv (live creds); added test-ssh/.testenv.example placeholders.
- Removed plans/ and planned-updates/ (deployment-planning docs) so no client/
  deployment domains appear in the public repo.
- All other secret stores were already gitignored.
- docs.coopcloud.tech retained as a submodule (public upstream).

recipe-info/immich/upstream.md

@@ -0,0 +1,16 @@
+# Immich Upstream
+
+## Main Project
+
+- **Repository:** https://github.com/immich-app/immich
+- **Releases:** https://github.com/immich-app/immich/releases
+- **Website:** https://immich.app
+
+## Images
+
+| Service | Image | Release Notes |
+|---------|-------|---------------|
+| app | `ghcr.io/immich-app/immich-server` | https://github.com/immich-app/immich/releases |
+| immich-machine-learning | `ghcr.io/immich-app/immich-machine-learning` | https://github.com/immich-app/immich/releases |
+| redis | `docker.io/valkey/valkey` | https://github.com/valkey-io/valkey/releases |
+| database | `ghcr.io/immich-app/postgres` | https://github.com/immich-app/immich/releases |