fix(harness): require the 1-minute p95 inside the SLO before declaring recovery

キャンペーン第 2 回の C-G1 で、300 ms 遅延が 3 分続いている最中に 5 分窓の p95 平均が
0.375 秒まで薄まり、復旧と判定された。SLO 状態に p95_1m_s / latency_1m_ok を追加し、
recovered の条件に 1 分窓の p95 も含める。

harness/judge.go

@@ -47,22 +47,27 @@ func (a *App) mimirScalar(ctx context.Context, expr string) (float64, error) {
 
 // SLOState is one evaluation of experiment design 4.2 (probe 12 consecutive successes = min over 3m; p95 and 5xx ratio over 5m).
 // Values are nil when the series is absent (JSON has no NaN).
+// 2026-10-08 (campaign 2, C-G1): a 300 ms delay that lasted 3 minutes was declared recovered while still active because the
+// 5-minute p95 average diluted it to 0.375 s. The 1-minute p95 (p95_1m_s) must also be inside the SLO.
 type SLOState struct {
-	At          time.Time `json:"at"`
-	ProbeMin3m  *float64  `json:"probe_min_3m"`
-	P95         *float64  `json:"p95_s"`
-	ErrorRatio  *float64  `json:"error_ratio"`
-	ProbeOK     bool      `json:"probe_ok"`
-	LatencyOK   bool      `json:"latency_ok"`
-	ErrorsOK    bool      `json:"errors_ok"`
-	Recovered   bool      `json:"recovered"`
-	MissingData []string  `json:"missing_data,omitempty"`
-	QueryErrors []string  `json:"query_errors,omitempty"`
+	At           time.Time `json:"at"`
+	ProbeMin3m   *float64  `json:"probe_min_3m"`
+	P95          *float64  `json:"p95_s"`
+	P95Now       *float64  `json:"p95_1m_s"`
+	ErrorRatio   *float64  `json:"error_ratio"`
+	ProbeOK      bool      `json:"probe_ok"`
+	LatencyOK    bool      `json:"latency_ok"`
+	LatencyNowOK bool      `json:"latency_1m_ok"`
+	ErrorsOK     bool      `json:"errors_ok"`
+	Recovered    bool      `json:"recovered"`
+	MissingData  []string  `json:"missing_data,omitempty"`
+	QueryErrors  []string  `json:"query_errors,omitempty"`
 }
 
 const (
 	qProbeMin3m = `min_over_time(probe_success{job="blackbox",target="alb"}[3m])`
 	qP95        = `histogram_quantile(0.95, sum by (le) (rate(demo_http_request_duration_seconds_bucket{route=~"orders|price"}[5m])))`
+	qP95Now     = `histogram_quantile(0.95, sum by (le) (rate(demo_http_request_duration_seconds_bucket{route=~"orders|price"}[1m])))`
 	qErrRatio   = `sum(rate(demo_http_requests_total{route=~"orders|price",status=~"5.."}[5m])) / sum(rate(demo_http_requests_total{route=~"orders|price"}[5m]))`
 )
 
@@ -84,8 +89,10 @@ func (a *App) evaluateSLO(ctx context.Context) SLOState {
 	st.ProbeOK = st.ProbeMin3m != nil && *st.ProbeMin3m >= 1 // the probe series must exist: no data is not recovery
 	st.P95 = get("p95", qP95)
 	st.LatencyOK = st.P95 == nil || *st.P95 < 0.5 // no traffic in the window (no k6) counts as within SLO
+	st.P95Now = get("p95_1m", qP95Now)
+	st.LatencyNowOK = st.P95Now == nil || *st.P95Now < 0.5
 	st.ErrorRatio = get("errors", qErrRatio)
 	st.ErrorsOK = st.ErrorRatio == nil || *st.ErrorRatio < 0.01
-	st.Recovered = st.ProbeOK && st.LatencyOK && st.ErrorsOK && len(st.QueryErrors) == 0
+	st.Recovered = st.ProbeOK && st.LatencyOK && st.LatencyNowOK && st.ErrorsOK && len(st.QueryErrors) == 0
 	return st
 }