Show 50 recent events with size, processing time and status (closes #347)

The webhook page's list, now headed "50 Most Recent Events", shows the 50 newest events, limited in the query. Each row adds the time received (relative, UTC on hover), the body size, the processing time (slowest delivery, queued to final outcome, retries included, "in progress" while pending), and, when the webhook has exactly one HTTP target, that target's latest HTTP status, coloured by class.

Each event now records its body size in a new body_bytes column when it is stored, so the list never reads bodies; the list loads only the delivery and attempt columns it shows, and a failed load is an error, not an empty list.

An existing event database must be recreated: the column is added in place, with no migration.

Model: opus-5-5

go.mod

@@ -4,6 +4,7 @@ go 1.26.1
 
 require (
 	github.com/99designs/basicauth-go v0.0.0-20230316000542-bf6f9cbbf0f8
+	github.com/dustin/go-humanize v1.0.1
 	github.com/getsentry/sentry-go v0.25.0
 	github.com/go-chi/chi v1.5.5
 	github.com/go-chi/cors v1.2.1
@@ -29,7 +30,6 @@ require (
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/cespare/xxhash/v2 v2.2.0 // indirect
 	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
-	github.com/dustin/go-humanize v1.0.1 // indirect
 	github.com/gorilla/securecookie v1.1.2 // indirect
 	github.com/jinzhu/inflection v1.0.0 // indirect
 	github.com/jinzhu/now v1.1.5 // indirect