feat: add eLabFTW Cloudron package (Business-Apps) [#669]

Official-image wrapper of elabftw/elabimg 5.6.12 (tag+digest pinned);
localstorage + mysql + ldap addons; httpPort 443 via DISABLE_HTTPS.
No OIDC upstream -> native LDAP flagged auth-risk. First mysql-addon
and first Business-Apps package; 15/~57. Build verified green under
ukrrs-batch.slice. Docs synced (JOURNAL s15, README, STATUS).

Detail + verification: https://projects.knownelement.com/issues/669#note-3938

README.md

@@ -9,9 +9,9 @@ The Cloudron component focuses on packaging upstream free/libre/open application
 ### 📊 Current Progress
 
 - **Total Applications**: ~57 (see [GitUrlList.txt](GitUrlList.txt))
-- **Completed Packages**: 14/~57 (~25%)
+- **Completed Packages**: 15/~57 (~26%)
 - **Packaging Templates**: Created ✅
-- **Packages Committed & Pushed**: 14 ✅
+- **Packages Committed & Pushed**: 15 ✅
 - **Build Tickets**: 46 filed (#633-#678, umbrella
   [#632](https://projects.knownelement.com/issues/632), Redmine project 55);
   grist-core excluded (packaged upstream)
@@ -36,6 +36,7 @@ The Cloudron component focuses on packaging upstream free/libre/open application
 | 12 | Database Gateway | Infrastructure | 93.7MB | 8080 | localstorage, postgresql | ✅ Committed |
 | 13 | FX | DevOps-Tools | 3.55GB | 8000 | localstorage (auth proxy) | ✅ Committed |
 | 14 | ChirpStack | Infrastructure | 83.4MB | 8080 | localstorage, postgresql, redis | ✅ Committed |
+| 15 | eLabFTW | Business-Apps | ~209MB (compressed) | 443 | localstorage, mysql, ldap | ✅ Committed |
 
 ### 📦 Packages in Development