Clean catalog legacy and align documentation with the simplified architecture

[vitormattos]

Context

The current github-workflows tree contains documentation and generated files that reflect earlier architecture decisions.

Examples include:

• documentation saying github-workflows is the source of truth;
• workflow-family-decisions.md describing release-nextcloud-app.yml as cataloged although the current catalog no longer lists it;
• a retired release-nextcloud-app.yml generated template still present on disk;
• release documentation that should move to release-tool.

Goal

Carry only current organization-catalog responsibilities into this repository and remove obsolete architecture/documentation rather than copying it forward.

No-legacy rule

Migration is not a preservation exercise. Files, workflows, scripts, manifests, tests, documentation, compatibility paths, or generated outputs that are no longer part of the intended architecture must be deleted from the source repository rather than copied to .github.

In particular, workflow-templates/release-nextcloud-app.yml is retired, is not present in the current catalog manifest, and must be removed from github-workflows; it must not be migrated to this repository.

The same rule applies to any other stale artifact discovered during the migration.

Requirements

• Reconcile the catalog manifest, template directory and documentation.
• Delete retired release templates and their metadata/tests/references from github-workflows; do not migrate them.
• Identify other files that are only remnants of superseded designs and delete them rather than carrying them forward.
• Move release-product documentation to release-tool.
• Keep organization-level documentation for workflow adoption, upstream adaptation, dependency policy and cross-repository synchronization here.
• Update terminology so .github is the source of truth rather than a publication target.
• Review all migrated documentation against the resulting implementation after migration.
• Finish with a repository-wide search for stale architecture names, retired workflows and obsolete compatibility paths.

Done when

• this repository describes only the architecture that actually runs;
• no retired workflow or legacy compatibility artifact was migrated merely because it existed in github-workflows;
• obsolete source files have been removed from github-workflows;
• documentation contains no obsolete github-workflows publication model.

[vitormattos]

Phase 0 cleanup started in LibreCodeCoop/github-workflows#182. The retired release-nextcloud-app workflow, its metadata/license sidecar, and the stale workflow-family documentation row are being deleted from the source repository rather than migrated. This directly resolves the known manifest/template/documentation inconsistency for that retired workflow.

[vitormattos]

The source-side retired-workflow cleanup landed in LibreCodeCoop/github-workflows#182 (c63cc243322c6c7d4fe6580adae6c8c9fa7ebe89) with all CI checks green. Catalog-side cleanup in this issue remains scheduled for Phase 3 after release-tool consolidation, per the super-epic order.

[vitormattos]

Completed.

The simplified architecture is now reflected in code and docs:

• release ownership points to LibreCodeCoop/release-tool;
• catalog/synchronization ownership points to LibreCodeCoop/.github;
• release lifecycle and nightly templates no longer use github-workflows runtime;
• App Store publication template now uses Release Tool PHAR commands (PR refactor: run App Store publisher through release-tool #66);
• the old catalog publication hop and repository-specific legacy are being removed from github-workflows in its retirement PR #183.

Current consumer workflows are materialized from this repository and no compatibility shim was introduced.