SAP GUI session times out with 'Maximum idle time exceeded' on self-hosted VM

[HappyDevs1]

On our self-hosted Windows VM, the SAP GUI session we keep logged in for recording/running flows periodically hits "Maximum idle time exceeded" and gets logged out. Any flow that then tries to attach to it fails, since there's no logged-in session left.

Need a solution — e.g. a keep-alive/heartbeat against the session, adjusting the idle timeout on the SAP side, or auto re-login before a flow runs.

Not investigated yet — filing to track it.

[HappyDevs1]

Investigated. Most of the recovery mechanism already exists:

• `connect()` in `sap_com.rs` already auto-logs in whenever it finds a session sitting at SAP's login screen, given `SAP_USER`/`SAP_PASSWORD` (built in `0e32af0` for sap: navigate() doesn't wait for the backend before returning, causing precondition timeouts on slower networks #226 - same failure mode).
• The nightly `sap-e2e.yml` workflow already benefits fully from this: `sap-session-bootstrap.ps1` + those secrets mean a session that idled out overnight self-heals on the next scheduled run.

The actual gap is between CI runs: nothing triggers an attach on a timer when someone's using the VM interactively, so the same self-healing path never fires until the next flow happens to run and fails.

Fix: #453 adds `scripts/sap-keep-alive.ps1`, a heartbeat meant to be registered as a Windows Scheduled Task (every 5-10 min) that bootstraps the session and pings it via the existing `session-status.flow.yaml`, triggering auto-login on a schedule instead of reactively. No Rust changes.

Complementary, outside this repo: raising the SAP-side idle-timeout profile parameter (`rdisp/gui_auto_logout` or equivalent) for this technical/service user would reduce how often this triggers at all - worth raising with whoever owns SAP Basis, not blocking on it here.