Open SQLite with WAL and bound delivery re-dispatch by ownership (closes #256)

internal/handlers/event_body.go

@@ -92,11 +92,10 @@ func (h *Handlers) HandleEventBodyDownload() http.HandlerFunc {
 // once per range.
 //
 // One consequence is worth keeping in view: the read finishes
-// before the client is written to, so no read lock is held for
-// the length of a slow download. These per-webhook databases
-// run in SQLite's default journal mode rather than WAL, so a
-// lock held that long would block the receiver from recording
-// new events.
+// before the client is written to, so nothing is held open for
+// the length of a slow download. Under WAL a read no longer
+// blocks the receiver, but it does pin the WAL against
+// checkpointing, and a download can last minutes.
 func (h *Handlers) serveEventBody(
 	w http.ResponseWriter,
 	r *http.Request,