discover.yml sets llm_existing_gemma_unit_found, but main.yml imports each
phase file with import_tasks + a distinct per-phase tag. Tags on
import_tasks apply to the whole file, so --tags verify (a supported,
documented way to re-run just this phase) skips discover.yml, leaving
the fact undefined. The stop task's 'default(false)' silently no-op'd,
so re-running verify alone against a host with Gemma still running would
start both new instances on top of it -- the OOM this task exists to
prevent.
Fix: gather service_facts and set the fact locally in verify.yml too,
only when not already defined, so the guard works regardless of which
tags were selected.
a76ad3195c