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).

test-ssh/ssh-config.example

@@ -0,0 +1,9 @@
+Host something.mytestserver.net
+        User myuser
+        IdentityFile /workspace/test-ssh/test-ssh-keys/mytestsshkey
+        Port 2246
+
+Host something2.mytestserver.net
+        User root
+        IdentityFile /workspace/test-ssh/test-ssh-keys/mytestsshkey
+        Port 22