refactor: align Bridgehead OVIS CCP overlay with upstream runtime contracts

Apply the PR #375 review feedback by removing Bridgehead-specific compose/setup overrides
that duplicated upstream OVIS behavior and by switching to the upstream-built Mongo image
that already contains init logic.
- rename CCP OVIS services to consistent upstream-style names (`ovis-*`) and update internal dependencies
- switch Mongo service image from direct `mongo:latest` + host-mounted init script to `docker.verbis.dkfz.de/ovis/ovis-backend-mongodb:latest`
- remove obsolete Mongo init bind mount (`/docker-entrypoint-initdb.d/init.js`) from compose
- drop redundant runtime overrides from compose (`restart`, `command`, `user`, `working_dir`)
- remove duplicated app-default/preprocessor env overrides (`OVIS_PREPROC_*`, misc backend defaults) and keep deployment wiring only
- fix Mongo connection env usage to `ADDRESS` and point services to `ovis-backend-database-mongodb`
- remove temporary root-compat Traefik redirect shim and keep mounted `/ccp-ovis` routing labels
- remove setup-time generation of Mongo init.js and related cache directory prep from `ccp/modules/ovis-setup.sh`

ccp/modules/ovis-setup.sh

@@ -4,30 +4,6 @@ if [ -n "$ENABLE_OVIS" ]; then
   if declare -F log >/dev/null 2>&1; then
     log INFO "OVIS setup detected -- will start OVIS services."
   fi
-  mkdir -p "/var/cache/bridgehead/ccp/ovis/mongo/init"
-  mkdir -p "/var/cache/bridgehead/ccp/ovis/shared_data"
-
-  cat >"/var/cache/bridgehead/ccp/ovis/mongo/init/init.js" <<'EOF'
-db = db.getSiblingDB("onc_test");
-db.createCollection("user");
-db.user.updateOne(
-  { _id: "OVIS-Root" },
-  {
-    $setOnInsert: {
-      _id: "OVIS-Root",
-      createdAt: new Date(),
-      createdBy: "system",
-      role: "super-admin",
-      status: "active",
-      pseudonymization: false,
-      darkMode: false,
-      colorTheme: "CCCMunich",
-      language: "de"
-    }
-  },
-  { upsert: true }
-);
-EOF
 
   OVERRIDE+=" -f ./$PROJECT/modules/ovis-compose.yml"
 fi