cluster0: lab seeds, Gitea mirrors, compose mail, verify tooling

Freeze lab-seeds backend for COMPOSE_SKIP_MONOLITH; fix Gitea mirror scripts
for 1.25 API; add secrets.lab.env template, verify-mail-lab, LAB_PUBLIC_ORIGIN,
and credentials pointers for mirror token recovery.

Co-authored-by: Cursor <cursoragent@cursor.com>

sim/cluster0/verify_global_setup.sh

@@ -11,7 +11,8 @@ export JOURNAL_PHASE=verify_global
 ensure_shared_mounted
 
 FAIL=0
-ORIGIN="${PUBLIC_ORIGIN%/}"
+ORIGIN="${LAB_PUBLIC_ORIGIN:-${PUBLIC_ORIGIN}}"
+ORIGIN="${ORIGIN%/}"
 
 check_url() {
   _path="$1"