REUSE-WP-0019-T03: add Forgejo Actions workflows (part 2 of prior commit)

The .forgejo/workflows/ files and doc updates described in 4862ed6 didn't
actually get staged there (git add silently skipped them after an earlier
pathspec miss on the already-deleted .gitea file) -- committing them now.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

registry/capabilities/capability.registry.validate.md

@@ -77,7 +77,7 @@ relations:
 evidence:
   documentation:
     - tools/README.md
-    - .gitea/workflows/ci.yml
+    - .forgejo/workflows/ci.yml
   tests:
     - tests/test_registry.py
   consumer_feedback: