v1.0.2 - Fix .env notification config

Fixed

• .env-based notification config never actually worked. linux_vitals_dotenv_slack_webhook_url (and the four other linux_vitals_dotenv_* secrets: generic webhook URL, SMTP host/username/password) referenced linux_vitals_dotenv_contents from within the same set_fact call that defined it -- the same same-task self-reference bug as the 1.0.1 bootloader fix, except here it failed silently (Ansible's regex_findall on an Undefined value fell through the | default('', true) chain to an empty string) instead of erroring, so it went undetected through every prior test and release. Every channel that relied on .env as a fallback (rather than an explicit inventory/group_vars value) was silently skipped. Split vitals_report/tasks/config.yml's first task into two sequential tasks. Verified by re-running against the live Multipass fleet: the Slack notification task changed from skipping to ok and the webhook received an actual HTTP POST.