chore: retire .mokogitea/manifest.xml doc/comment references

Platform detection already reads the MokoGitea metadata API on dev; this removes
leftover manifest.xml references from docs and comments (CLAUDE.md, auto-release
comments, pr-check comment tail, CONTRIBUTING). Joomla EXTENSION manifest refs
left intact.

.mokogitea/workflows/auto-release.yml

@@ -8,13 +8,13 @@
 # REPO: https://git.mokoconsulting.tech/mokoconsulting-tech/mokocli
 # PATH: /templates/workflows/universal/auto-release.yml.template
 # VERSION: 05.01.00
-# BRIEF: Universal build & release � detects platform from manifest.xml
+# BRIEF: Universal build & release � detects platform from metadata API
 #
 # +=======================================================================+
 # |              UNIVERSAL BUILD & RELEASE PIPELINE                        |
 # +=======================================================================+
 # |                                                                        |
-# |  Reads manifest.xml (joomla|dolibarr|generic) to branch logic.       |
+# |  Reads metadata API (joomla|dolibarr|generic) to branch logic.       |
 # |                                                                        |
 # |  Platform-specific:                                                    |
 # |    joomla:   XML manifest, type-prefixed packages                      |

CONTRIBUTING.md

@@ -119,7 +119,7 @@ This ensures Joomla sites on ANY stability channel see the update (Joomla only s
 
 The version tools update all files containing version stamps:
 
-- `.mokogitea/manifest.xml` (canonical source)
+- Language-appropriate version file (canonical source; e.g. `package.json`, `pyproject.toml`, or Go `internal/version`)
 - Joomla XML manifests (`<version>` tag)
 - `README.md`, `CHANGELOG.md` (`VERSION:` pattern)
 - `package.json`, `pyproject.toml`