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).

settings.toml.example

@@ -0,0 +1,11 @@
+default_instance = "t2cc"
+
+[instances.b1cc]
+server = "b1cc.commoninternet.net"
+domain_suffix = "b1cc.commoninternet.net"
+protected_recipes = ["traefik", "backup-bot-two"]
+
+[instances.t1cc]
+server = "t2cc.commoninternet.net"
+domain_suffix = "t2cc.commoninternet.net"
+protected_recipes = ["traefik", "backup-bot-two"]