Give each event its own page and show bodies the same everywhere (closes #369)

Each row of the recent events on the webhook page links to the
event's own page, /hook/{id}/events/{eventID}, and expands to show its
body; only the newest starts expanded. The event's page shows its
details, its whole body and every delivery with its attempts.

One renderer, newBodyView with templates/event_body.html, shows a body
in all three places: whole up to 32 KiB, cut there in the lists with a
link to the event's page, JSON pretty-printed, a body of more than 200
lines or 32 KiB in a scrolling box, and a body that is not text left
out beside its download link. A resubmitted copy links to its
original's page.

Model: opus-5-5

internal/handlers/event_log_view.go

@@ -5,14 +5,6 @@ import (
 	"unicode/utf8"
 )
 
-// maxRenderedBodyBytes caps how many bytes of a stored event
-// body reach the event log page. Bodies come from the
-// unauthenticated receiver under the 1 MB ingest cap and
-// renderTemplate buffers a whole page before writing it, so
-// an uncapped page of paginationPerPage events is tens of
-// megabytes of resident memory per concurrent viewer.
-const maxRenderedBodyBytes = 8192
-
 // eventLogColumns is the event log's projection. The casts to
 // blob are load-bearing: they make substr and length count
 // bytes rather than characters, so the cap bounds the page in
@@ -24,27 +16,23 @@ const eventLogColumns = "id, created_at, method, content_type, " +
 	"substr(cast(body as blob), 1, ?) AS body, " +
 	"length(cast(body as blob)) AS body_bytes"
 
+// eventColumns is eventLogColumns for the event's own page, which
+// shows the whole body.
+const eventColumns = "id, created_at, method, content_type, " +
+	"resubmitted_from_id, " +
+	"cast(body as blob) AS body, " +
+	"length(cast(body as blob)) AS body_bytes"
+
 // EventLogView is the display-safe projection of an event for
-// the event log page, alongside DeliveryView and TargetView.
-// It carries a capped body plus the true stored size, so the
-// page can mark a body as truncated without ever holding the
-// whole thing.
+// the event log page and the event's own page, alongside
+// DeliveryView and TargetView.
 type EventLogView struct {
 	ID          string
 	CreatedAt   time.Time
 	Method      string
 	ContentType string
 
-	// Body holds at most maxRenderedBodyBytes bytes of the
-	// stored body.
-	Body string
-
-	// BodyBytes is the true size of the stored body.
-	BodyBytes int64
-
-	// BodyTruncated reports that the stored body was larger
-	// than the cap, so the page owes the reader a marker.
-	BodyTruncated bool
+	Body BodyView
 
 	// ResubmittedFromID names the event this one was copied
 	// from, empty for an event that arrived on the receiver.
@@ -65,16 +53,10 @@ func (v EventLogView) ResubmittedFrom() bool {
 	return v.ResubmittedFromID != ""
 }
 
-// BodyShownBytes is how many body bytes the page is actually
-// rendering, which the truncation marker reports beside the
-// true size.
-func (v EventLogView) BodyShownBytes() int {
-	return len(v.Body)
-}
-
-// eventLogRow is one row of the event log projection. Its
-// body column arrives already cut to the cap by SQLite, with
-// the true size beside it.
+// eventLogRow is one row of the event log projection, or of
+// eventColumns. In the event log its body column arrives
+// already cut to the cap by SQLite, with the true size beside
+// it.
 type eventLogRow struct {
 	ID                string
 	CreatedAt         time.Time
@@ -85,31 +67,22 @@ type eventLogRow struct {
 	BodyBytes         int64
 }
 
-// view projects a loaded row for rendering.
-func (r *eventLogRow) view() EventLogView {
-	body := r.Body
-	truncated := r.BodyBytes > int64(len(body))
-
-	// Only a cut body can have been left mid-sequence by
-	// this query. A whole body is passed through exactly as
-	// stored, however malformed.
-	if truncated {
-		body = trimPartialRune(body)
-	}
-
+// view projects a loaded row of the webhook's events for
+// rendering.
+func (r *eventLogRow) view(webhookID string) EventLogView {
 	var from string
 	if r.ResubmittedFromID != nil {
 		from = *r.ResubmittedFromID
 	}
 
 	return EventLogView{
-		ID:                r.ID,
-		CreatedAt:         r.CreatedAt,
-		Method:            r.Method,
-		ContentType:       r.ContentType,
-		Body:              string(body),
-		BodyBytes:         r.BodyBytes,
-		BodyTruncated:     truncated,
+		ID:          r.ID,
+		CreatedAt:   r.CreatedAt,
+		Method:      r.Method,
+		ContentType: r.ContentType,
+		Body: newBodyView(
+			"/hook/"+webhookID+"/events/"+r.ID, r.Body, r.BodyBytes,
+		),
 		ResubmittedFromID: from,
 	}
 }