A /p/<profile>/ cron_job route resolved and fired the job from the gateway's
default home: `_fire_cron_job` ran `execute_job_for_event` outside
`_profile_scope`, so `cron/jobs.json` lookups (`resolve_job_ref`,
`claim_job_for_fire`) and the run's config/secrets came from the wrong
profile — the agent-mode path already scopes its run, this path did not.
`asyncio.to_thread` copies contextvars, so wrapping the call is enough.
Route-level `skills` were also being injected into the rendered prompt on
cron_job routes even though the docs say they are ignored (the job's own
skills apply); skip `_apply_skills` for cron_job routes so the per-run
context stays plain event text.
Test proven red on the pre-fix tree (home resolved to the default profile),
green after.