Event log: only the newest event expanded, and only the 50 most recent (closes #349)

The event log now loads the 50 newest events in its query and opens
only the newest on load, as the recent events on a webhook's page
already do. With 50 at most there is never a second page, so paging is
gone: the page links, the `page` query parameter, the page number that
Replay and Resubmit carried back to the log, and `pageOrFirst` with its
test. The count beside the heading reads "50 most recent of N events"
when there are more. The comments and README lines that named `page` as
the query parameter the service reads now name `next` and `notice`.

Model: opus-5-5

internal/handlers/source_management.go

@@ -1112,30 +1112,17 @@ func (h *Handlers) HandleSourceLogs() http.HandlerFunc {
 			return
 		}
 
-		page := h.parsePage(r)
-
 		evts, total, ok := h.loadEventsWithDeliveries(
-			w, r, webhook, targets, page,
+			w, r, webhook, targets,
 		)
 		if !ok {
 			return
 		}
 
-		totalPages := int(total) / paginationPerPage
-		if int(total)%paginationPerPage != 0 {
-			totalPages++
-		}
-
 		data := map[string]any{
 			tmplKeyWebhook: &webhook,
 			"Events":       evts,
-			"Page":         page,
-			"TotalPages":   totalPages,
 			"TotalEvents":  total,
-			"HasPrev":      page > 1,
-			"HasNext":      page < totalPages,
-			"PrevPage":     page - 1,
-			"NextPage":     page + 1,
 		}
 
 		h.renderTemplate(w, r, "source_logs.html", data)
@@ -1195,15 +1182,11 @@ func (h *Handlers) loadTargetMap(
 	return targetMap, nil
 }
 
-// parsePage extracts a page number from the query string.
-func (h *Handlers) parsePage(r *http.Request) int {
-	return pageOrFirst(r.URL.Query().Get("page"))
-}
-
-// loadEventsWithDeliveries loads paginated events and their
-// deliveries from the per-webhook database. Events come back
-// as capped projections rather than database.Event rows: see
-// eventLogColumns for why the cut happens in SQL.
+// loadEventsWithDeliveries loads the recentEventLimit newest events
+// and their deliveries from the per-webhook database, and the total
+// number of events stored. Events come back as capped projections
+// rather than database.Event rows: see eventLogColumns for why the
+// cut happens in SQL.
 //
 // The bool reports whether the load succeeded. It is false
 // once this has answered the request with an error, and the
@@ -1213,7 +1196,6 @@ func (h *Handlers) loadEventsWithDeliveries(
 	r *http.Request,
 	webhook database.Webhook,
 	targetMap map[string]eventLogTarget,
-	page int,
 ) ([]EventLogView, int64, bool) {
 	if !h.dbMgr.DBExists(webhook.ID) {
 		return nil, 0, true
@@ -1228,9 +1210,7 @@ func (h *Handlers) loadEventsWithDeliveries(
 		return nil, 0, false
 	}
 
-	rows, totalEvents := loadEventLogRows(
-		webhookDB, webhook.ID, page,
-	)
+	rows, totalEvents := loadEventLogRows(webhookDB, webhook.ID)
 
 	result, ok := h.eventLogViews(
 		w, r, webhookDB, webhook.ID, rows, targetMap,
@@ -1303,10 +1283,11 @@ func (h *Handlers) eventLogViews(
 	return result, true
 }
 
-// loadEventLogRows reads one page of the event log projection, newest
-// first, and the total number of events the pager counts against.
+// loadEventLogRows reads the event log projection of the
+// recentEventLimit newest events, newest first, and the total number
+// of events stored.
 func loadEventLogRows(
-	webhookDB *gorm.DB, webhookID string, page int,
+	webhookDB *gorm.DB, webhookID string,
 ) ([]eventLogRow, int64) {
 	var totalEvents int64
 
@@ -1320,9 +1301,7 @@ func loadEventLogRows(
 		eventLogColumns, maxRenderedBodyBytes,
 	).Where(
 		"webhook_id = ?", webhookID,
-	).Order("created_at DESC").Offset(
-		(page - 1) * paginationPerPage,
-	).Limit(paginationPerPage).Find(&rows)
+	).Order("created_at DESC").Limit(recentEventLimit).Find(&rows)
 
 	return rows, totalEvents
 }
@@ -1331,9 +1310,9 @@ func loadEventLogRows(
 // events have been resubmitted from it.
 //
 // One grouped query covers the page rather than one query per event.
-// A page holds paginationPerPage ids, far below SQLite's bound
-// parameter ceiling, so it needs no chunking as the delivery result
-// load does.
+// The page shows at most recentEventLimit events, far below SQLite's
+// bound parameter ceiling, so it needs no chunking as the delivery
+// result load does.
 func resubmitCounts(
 	webhookDB *gorm.DB, eventIDs []string,
 ) (map[string]int, error) {
@@ -1759,24 +1738,6 @@ func (h *Handlers) setTargetFromForm(
 	return "", nil
 }
 
-// pageOrFirst parses a paginated page number, answering 1 for
-// anything empty, unparseable or out of range.
-//
-// Falling back rather than rejecting is correct here and only here:
-// a page number is where to send the browser next, not configuration
-// the operator is storing, and the actions that submit one have
-// already completed by the time it is read — answering 400 would
-// report a failure that did not happen. Anything an operator SETS
-// must be validated instead; see parseMaxRetries.
-func pageOrFirst(s string) int {
-	v, err := strconv.Atoi(strings.TrimSpace(s))
-	if err != nil || v < 1 {
-		return 1
-	}
-
-	return v
-}
-
 // targetFormInput carries the raw values of a target form. Both the
 // create and the edit path fill one and hand it to setTargetFromForm,
 // so neither can come to validate a target differently from the