Forced stop finds a database process that has only just started #5116

What happens

On Linux, a Steampipe database process that has only just started can briefly report an empty command line. The scan that finds running Steampipe database processes matches on that command line, so it skips the new process. steampipe service stop --force and the check made before a database backup can then miss a database that is running.

Found while fixing the flaky test in #5113 (PR #5115), which hit exactly this window.

Why it matters

A forced stop can report success while a database it should have stopped keeps running, and a backup can start alongside a database it believes is not there.

Success criteria

• On Linux, a Steampipe database process started from the install directory is found by steampipe service stop --force even when it is stopped within a moment of starting.
• A test covers a database process whose command line reads as empty when first scanned, and fails without the change.
• Processes not started by Steampipe are still never matched.

Out of scope

• macOS process scanning, which has not shown this window.