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/handlers/recent_events_test.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"net/http"
 	"net/http/httptest"
+	"strconv"
 	"strings"
 	"testing"
 	"time"
@@ -301,6 +302,73 @@ func TestHandleSourceDetail_NoStatusWithoutSingleHTTPTarget(
 	}
 }
 
+// TestHandleSourceDetail_RecentEventsLinkAndExpand proves each row
+// links to its event's own page and expands to show its body, and
+// that only the newest row starts expanded.
+func TestHandleSourceDetail_RecentEventsLinkAndExpand(t *testing.T) {
+	t.Parallel()
+
+	f := newRecentEventsFixture(t)
+	now := time.Now()
+
+	older := f.event(
+		t, contentTypeJSON, `{"which":"older"}`, now.Add(-time.Minute),
+	)
+	newer := f.event(t, contentTypeJSON, `{"which":"newer"}`, now)
+
+	body := f.render(t)
+
+	for _, e := range []*database.Event{older, newer} {
+		assert.Contains(
+			t, body, `href="/hook/`+f.webhook.ID+`/events/`+e.ID+`"`,
+		)
+	}
+
+	assert.Equal(t, 2, strings.Count(body, `<div x-show="open" x-cloak class="mt-3">`))
+	assert.Equal(t, 1, strings.Count(body, " data-open>"))
+
+	open := strings.Index(body, " data-open>")
+	newerBody := strings.Index(body, "&#34;which&#34;: &#34;newer&#34;")
+	olderBody := strings.Index(body, "&#34;which&#34;: &#34;older&#34;")
+
+	assert.Less(t, open, newerBody, "the newest row is not the open one")
+	assert.Less(t, newerBody, olderBody)
+}
+
+// TestHandleSourceDetail_RecentEventBodyCut proves a body up to
+// the cap is shown whole and pretty-printed, and a larger one only
+// its first bodyCap bytes, as received, with links to the whole
+// body on the event's page and to the download.
+func TestHandleSourceDetail_RecentEventBodyCut(t *testing.T) {
+	t.Parallel()
+
+	f := newRecentEventsFixture(t)
+	now := time.Now()
+
+	// A JSON document of n bytes.
+	document := func(n int) string {
+		return `{"pad":"` + strings.Repeat("x", n-len(`{"pad":""}`)) + `"}`
+	}
+
+	whole := f.event(
+		t, contentTypeJSON, document(bodyCap), now.Add(-time.Minute),
+	)
+	cut := f.event(t, contentTypeJSON, document(bodyCap+1), now)
+
+	body := f.render(t)
+	eventURL := `href="/hook/` + f.webhook.ID + `/events/`
+
+	assert.Equal(t, 1, strings.Count(body, "{\n  &#34;pad&#34;: "))
+	assert.Contains(t, body, "{&#34;pad&#34;:&#34;xxx")
+	assert.Contains(
+		t, body,
+		"Showing the first "+strconv.Itoa(bodyCap)+" of "+
+			strconv.Itoa(bodyCap+1)+" bytes, unformatted.",
+	)
+	assert.Contains(t, body, eventURL+cut.ID+`/body"`)
+	assert.NotContains(t, body, eventURL+whole.ID+`/body"`)
+}
+
 // TestHandleWebhook_RecordsBodySize proves the receiver records the
 // body's size in bytes, not characters, with the event it stores.
 func TestHandleWebhook_RecordsBodySize(t *testing.T) {