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

Each event now has its own page at /hook/ID/events/EVENTID, behind the login, showing its details, its whole body and every delivery; a resubmitted copy links to its original's page. The recent events on the webhook page link there and expand to show their bodies, only the newest expanded on load. One renderer and one template show a body the same way in the recent events, the event log and the event's page: whole up to 32 KiB, cut there in the two lists with links to the event's page and the download; JSON pretty-printed unless that would grow it past four times plus 1 KiB; over 200 lines in a scrolling box; a body holding NUL or control characters treated as binary and never dumped raw.

Model: opus-5-5

internal/server/alpine_browser_test.go

@@ -39,6 +39,9 @@ const (
 	// the mobile menu button instead of the navigation links.
 	phoneWidth  = 390
 	phoneHeight = 844
+
+	// olderBody is the body of the event received before the newest.
+	olderBody = "the older event"
 )
 
 // TestAlpineRunsUnderTheSecurityPolicy loads the webhook page and the
@@ -63,6 +66,7 @@ func TestAlpineRunsUnderTheSecurityPolicy(t *testing.T) {
 			Active:    true,
 		},
 	).Error)
+	env.seedEvent(t, webhook.ID, olderBody)
 	event := env.seedEvent(t, webhook.ID, `{"hello":"browser"}`)
 	target := env.seedTarget(t, webhook.ID)
 	dlv := env.seedFailedDelivery(t, webhook.ID, event.ID, target.ID)
@@ -87,6 +91,7 @@ func TestAlpineRunsUnderTheSecurityPolicy(t *testing.T) {
 	checkTargetType(ctx, t, page+"/events")
 	checkCopy(ctx, t, page)
 	checkEntrypointEdit(ctx, t, page, page+"/events")
+	checkRecentEvents(ctx, t, page)
 	checkEventLog(ctx, t, page+"/events", event.ID, target.Name)
 	checkMobileMenu(ctx, t, page)
 
@@ -447,6 +452,46 @@ func checkEntrypointEdit(
 		"saving the edit form does not change the description")
 }
 
+// checkRecentEvents loads a webhook page and checks that of its recent
+// events only the newest starts expanded, showing its body, that
+// clicking the older one's row expands it and clicking again collapses
+// it, and that clicking the newest one's row collapses it. It then
+// follows the newest one's Open link to the event's own page, which
+// shows the body.
+func checkRecentEvents(ctx context.Context, t *testing.T, url string) {
+	t.Helper()
+
+	// The newest event's body is pretty-printed JSON. Each row's
+	// toggle is the button in the element that holds its state.
+	newest := `//pre[contains(., '"hello": "browser"')]`
+	older := `//pre[text()="` + olderBody + `"]`
+	toggle := `/ancestor::div[@x-data][1]//button`
+
+	require.NoError(t, chromedp.Run(ctx, loadPage(url)))
+
+	assert.True(t, shown(ctx, newest), "the newest event starts collapsed")
+	assert.True(t, hidden(ctx, older), "an older event starts expanded")
+
+	click(ctx, t, older+toggle)
+	assert.True(t, shown(ctx, older), "clicking an event does not expand it")
+
+	click(ctx, t, older+toggle)
+	assert.True(t, hidden(ctx, older),
+		"clicking an event again does not collapse it")
+
+	click(ctx, t, newest+toggle)
+	assert.True(t, hidden(ctx, newest),
+		"clicking the newest event does not collapse it")
+
+	require.NoError(t, chromedp.Run(ctx, loadPage(url)))
+	click(ctx, t, newest+`/ancestor::div[@x-data][1]//a[text()="Open"]`)
+
+	assert.True(t, shown(ctx, `//h2[text()="Body"]`),
+		"Open does not lead to the event's own page")
+	assert.True(t, shown(ctx, newest),
+		"the event's own page does not show its body")
+}
+
 // checkEventLog loads the event log and checks that clicking an event's
 // row expands it, that in there clicking its delivery shows the
 // delivery's attempts and clicking again hides them, and that clicking
@@ -459,7 +504,7 @@ func checkEventLog(
 	// The event's row shows its ID, and its Resubmit form is in the part
 	// that expands. The delivery's row there shows the target's name.
 	eventRow := `//span[text()="` + eventID + `"]`
-	expanded := `form[action$="/resubmit"]`
+	expanded := `form[action$="/` + eventID + `/resubmit"]`
 	deliveryRow := `//span[text()="` + targetName + `"]`
 	attempt := `//span[text()="Attempt 1"]`