* feat(schedules): auto-update stacks by Stack Label
Add a reusable selector_type/selector_value on scheduled tasks so admins
can schedule image updates against live Stack Label membership across the
fleet or one node, reusing fleet label resolution and the existing
auto-update orchestrator.
* fix(image-updates): sanitize auto-update execute failure logs
Use a static format string and sanitizeForLog so CodeQL no longer
flags user-controlled stack names and error text in the execute catch.
* fix(ui): space Scope label from fleet/node segmented control
Match the Schedule row layout so the inline SegmentedControl no longer
sits flush against the Scope label.
* fix(ui): remove redundant wrapper around Scope segmented control
Anso