[ivangrynenko]

The scan can now be turned on and off from a CI variable, without editing the workflow (truecms/sentinel#2014).

What changed

• New action input enabled. The example passes ${{ vars.SENTINEL_UPGRADE_SCAN }}, so a repository, organisation or environment variable turns the scan on (true) or off (false). Left out, the action reads the job's SENTINEL_UPGRADE_SCAN as before.
• The script accepts true, 1, yes, on and false, 0, no, off in any case. Empty or off passes the job without doing anything; any other value fails it.
• GitHub and GitLab examples no longer hard-code the switch; the README and the AI prompt say to set it as a variable.
• A CI job runs the action itself: off through the input, empty input, and the job variable fallback.

Access and exposure

Question	Answer
Who may reach it?	Unchanged. Only people who can edit the customer's CI variables can turn the scan on or off.
What stops everyone else?	GitHub and GitLab variable permissions. Sentinel still checks the scan key.
Is it released?	Sentinel's own route switch and rollout are unchanged.
What does it reveal?	The switch value only. The key and UUID are not read while the switch is off.
How is it tested?	Bats tests for each switch value, and the new action-switch CI job.

Checks run

• bats tests/upgrade-scan/scan.bats: 56 passed.
• shellcheck: clean. YAML parsed.
• Codex review (GPT-6.1 Terra, xhigh): see below.