Offer no Replay for a delivery to a deleted target (closes #387)

The event log offered Replay on a delivery whose target was deleted,
and the refusal told the operator to recreate the target and replay.
That cannot work: a recreated target is a new one the old delivery
does not name, so the replay is refused again. The Replay button is
now left off such a delivery, whose row already names the target as
deleted, and the refusal a page left open can still reach now points
to Resubmit, which sends the event to the webhook's currently active
targets.

Model: opus-5-5

internal/handlers/source_logs_deleted_target_test.go

@@ -94,6 +94,44 @@ func TestHandleSourceLogs_NamesDeletedTarget(t *testing.T) {
 	)
 }
 
+// TestHandleSourceLogs_OffersNoReplayForDeletedTarget proves a
+// finished delivery offers Replay while its target lives and not
+// once the target is deleted. A replay to a deleted target is always
+// refused, and recreating the target makes a new one that the old
+// delivery does not name.
+func TestHandleSourceLogs_OffersNoReplayForDeletedTarget(t *testing.T) {
+	t.Parallel()
+
+	var (
+		h     *handlers.Handlers
+		sess  *session.Session
+		db    *database.Database
+		dbMgr *database.WebhookDBManager
+	)
+
+	app := newTestApp(t, &h, &sess, &db, &dbMgr)
+	app.RequireStart()
+
+	t.Cleanup(app.RequireStop)
+
+	wh := seedWebhook(t, db)
+	tgt := seedTarget(t, db, wh.ID, database.TargetTypeLog)
+
+	_, failed := seedFailedDelivery(t, dbMgr, wh.ID, tgt.ID)
+	replayForm := `action="/hook/` + wh.ID + `/deliveries/` +
+		failed.ID + `/replay"`
+
+	before := renderSourceLogsPage(t, h, sess, wh.ID)
+	assert.Contains(t, before, replayForm)
+
+	deleteTargetThroughHandler(t, h, sess, wh.ID, tgt.ID)
+
+	after := renderSourceLogsPage(t, h, sess, wh.ID)
+	assert.NotContains(t, after, replayForm)
+	assert.NotContains(t, after, ">Replay<")
+	assert.Contains(t, after, tgt.Name+deletedMarker)
+}
+
 // TestHandleSourceLogs_MasksDeletedTargetConfig proves that
 // naming a deleted target does not widen what the page shows of
 // it: its stored configuration stays masked by exactly the rules