MTTD: was querying AuditLog for action names that don't match actual
logged actions. Now uses red_started_at → blue_started_at directly
(both stored on the Test record). Net of red_paused_seconds.
MTTR: was searching for remediation_status=completed (no data). Redefined
as total pipeline time: red_started_at → blue_validated_at net of all
paused time. Only counts fully validated tests.
Red avg time: was using red_validated_at - created_at (created_at NULL
for many tests). Now uses blue_started_at - red_started_at net paused.
Blue avg time: was using blue_validated_at - red_validated_at (wrong
phase boundary). Now uses blue_work_started_at (or blue_started_at
fallback) → blue_validated_at net of blue_paused_seconds.
06e8effaa4