Workspaces: auto-stop idle free workspaces (post-launch) #154

Context

Workspaces open to the whole community (helmcode/nan-cloud-api, branch feat/workspaces-launch-gates). The free workspace (1 vCPU / 2 GiB / 10 GiB) is now a premium benefit, plus two grandfathered €70 members. Free workspaces run 24/7 whether or not the member uses them, and they compete for the same fleet capacity as paid slots.

Owner decision (2026-10-06): auto-stopping idle free workspaces is not part of the launch. This issue tracks it for later.

Proposal

• Define "idle" from signals cloud-api already has or can get cheaply: no SSH-gateway / web-terminal session, no inference calls with the workspace key, no software job, for N days (e.g. 7).
• Stop (not delete) an idle FREE workspace with a distinct state_reason (e.g. idle), so restart is one click and the lifecycle arms (subscription stop / restore) never confuse it with an entitlement stop.
• Notify the member before and when it is stopped (Spanish, same style as the lifecycle notices).
• Never touch slot-paid workspaces (they are paid compute), rescue boots, or workspaces with a restore/software job in flight.
• Metric + Slack-only alert on the number stopped per pass.

Open questions

• Idle threshold and whether premium members get a longer one.
• Whether a stopped-for-idle VM keeps its host reservation (capacity) or frees it.