Event log: show attempt and delivery times, label replays, zone event times (closes #386)

In the event log and on an event's page, attempts and deliveries showed no time, event times had no zone, and a replay looked like the original it repeated. Each attempt now shows when its result was recorded and each delivery when it was created, as how long ago with the full UTC time on hover, and the event log's event times read the same way. A delivery created by Replay records it in a new `replay` column and is labelled a replay in the event's summary line and its delivery list; replays made before this change are not labelled. A delivery's row is now drawn by one template, `delivery_row`, that both pages share.

Model: opus-5-5

internal/handlers/delivery_result_view.go

@@ -3,6 +3,7 @@ package handlers
 import (
 	"time"
 
+	"github.com/dustin/go-humanize"
 	"sneak.berlin/go/webhooker/internal/delivery"
 )
 
@@ -47,6 +48,11 @@ type DeliveryResultView struct {
 	AttemptNum int
 	Success    bool
 
+	// Ran is how long ago the attempt was recorded, and RanUTC the
+	// full timestamp the page shows on hover.
+	Ran    string
+	RanUTC string
+
 	// StatusCode is 0 when the attempt never got a response,
 	// which is why the page asks HasStatusCode rather than
 	// printing the number.
@@ -160,6 +166,8 @@ func (r *deliveryResultRow) view(
 	return DeliveryResultView{
 		AttemptNum:         r.AttemptNum,
 		Success:            r.Success,
+		Ran:                humanize.Time(r.CreatedAt),
+		RanUTC:             r.CreatedAt.UTC().Format(time.DateTime) + " UTC",
 		StatusCode:         r.StatusCode,
 		Error:              redactor.Redact(r.Error),
 		DurationMS:         r.Duration,