fix(analyze): divide per-hour rates by time actually worked

A host asleep mid-run tested nothing, and charging that sleep to an arm reports
it slower for a reason unrelated to the arm. The legend also claimed wall clock
while the number was monotonic. Campaigns written before the split are still
read through the old field name so their run hours do not silently zero.

Claude-Session: https://claude.ai/code/session_01A5KmftdEJ49A9z5mF5ESrX

cmd/internal-tools/analyze/report.go

@@ -31,7 +31,8 @@ func writeReport(result analysis, out io.Writer) {
 		})
 
 	fmt.Fprintln(out)
-	fmt.Fprintln(out, "a detection is one distinct property violated in one run; run hours sum the per-run wall clock")
+	fmt.Fprintln(out, "a detection is one distinct property violated in one run; run hours sum the time the runs worked,")
+	fmt.Fprintln(out, "on the monotonic clock, so a host that slept mid-run is not charged for the sleep")
 	fmt.Fprintln(out, "actions count the steps that dispatched one; the rest chose nothing or had the choice thrown away")
 	writeTable(out, []string{"arm", "steps", "actions", "run hours", "detections", "defects/1k actions", "defects/hour", "distinct defects", "found in one run"},
 		func(add func(...string)) {