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/analysis_test.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"math"
+	"path/filepath"
 	"testing"
 	"time"
 )
@@ -11,7 +12,7 @@ func violatingRun(seed int64, steps, origin int, properties ...string) classifie
 		Seed:               seed,
 		Steps:              steps,
 		Actions:            steps,
-		DurationMillis:     60_000,
+		MonotonicMillis:    60_000,
 		OriginStep:         origin,
 		Violated:           true,
 		ViolatedProperties: properties,
@@ -19,7 +20,7 @@ func violatingRun(seed int64, steps, origin int, properties ...string) classifie
 }
 
 func cleanRun(seed int64, steps int) classifiedRun {
-	return classifiedRun{Seed: seed, Steps: steps, Actions: steps, DurationMillis: 60_000}
+	return classifiedRun{Seed: seed, Steps: steps, Actions: steps, MonotonicMillis: 60_000}
 }
 
 func TestSummarize_ArmWhereNoRunViolated(t *testing.T) {
@@ -85,9 +86,9 @@ func TestSummarize_CountsDispatchedActionsNotSteps(t *testing.T) {
 		Name:   "declines",
 		Budget: 40,
 		Runs: []classifiedRun{
-			{Seed: 1, Steps: 40, Actions: 10, DurationMillis: 3_600_000,
+			{Seed: 1, Steps: 40, Actions: 10, MonotonicMillis: 3_600_000,
 				Violated: true, OriginStep: 12, ViolatedProperties: []string{"cartTotal"}},
-			{Seed: 2, Steps: 40, Actions: 6, DurationMillis: 3_600_000},
+			{Seed: 2, Steps: 40, Actions: 6, MonotonicMillis: 3_600_000},
 		},
 	})
 	if summary.TotalSteps != 80 {
@@ -110,7 +111,7 @@ func TestSummarize_ArmThatDispatchedNothingHasNoPerActionRate(t *testing.T) {
 		Name:   "inert",
 		Budget: 20,
 		Runs: []classifiedRun{
-			{Seed: 1, Steps: 20, Actions: 0, DurationMillis: 3_600_000,
+			{Seed: 1, Steps: 20, Actions: 0, MonotonicMillis: 3_600_000,
 				Violated: true, OriginStep: 3, ViolatedProperties: []string{"cartTotal"}},
 		},
 	})
@@ -125,6 +126,43 @@ func TestSummarize_ArmThatDispatchedNothingHasNoPerActionRate(t *testing.T) {
 	}
 }
 
+func runHoursFor(t *testing.T, record map[string]any) float64 {
+	t.Helper()
+	directory := filepath.Join(t.TempDir(), "campaign")
+	record["seed"] = 1
+	writeCampaign(t, directory,
+		map[string]any{"arm": "seeded", "max_steps": 50, "seeds": []int{1}},
+		[]map[string]any{record})
+	arms, err := groupArms([]string{directory})
+	if err != nil {
+		t.Fatal(err)
+	}
+	return summarize(arms[0]).TotalRunHours
+}
+
+// A host asleep mid-run advanced the wall clock while testing nothing, so the
+// sleep has no place in the denominator of a per-hour rate.
+func TestSummarize_RunHoursCountTheTimeWorkedNotTheTimeThatPassed(t *testing.T) {
+	hours := runHoursFor(t, map[string]any{
+		"exit_code": 0, "steps": 50, "actions": 50,
+		"monotonic_millis": 3_600_000, "wall_clock_millis": 5_400_000,
+	})
+	if hours != 1 {
+		t.Errorf("run hours %v, want the 1 hour worked rather than the 1.5 hours that passed", hours)
+	}
+}
+
+// Campaigns recorded before the two clocks were split gave the same monotonic
+// reading the name duration_millis, and their hours still have to count.
+func TestSummarize_RunHoursReadCampaignsWrittenBeforeTheClocksWereSplit(t *testing.T) {
+	hours := runHoursFor(t, map[string]any{
+		"exit_code": 0, "steps": 50, "actions": 50, "duration_millis": 3_600_000,
+	})
+	if hours != 1 {
+		t.Errorf("run hours %v, want 1 from the older duration_millis field", hours)
+	}
+}
+
 func TestSummarize_ArmWithNoUsableRunsAfterExclusions(t *testing.T) {
 	summary := summarize(arm{
 		Name:   "broken",