Store and show an event's query string, and pass it on to an HTTP target when set (closes #312)

The receiver dropped the query string of every request it received, so a sender's URL parameters were silently lost. Each event now keeps it, as sent, in a new `raw_query` column of the per-webhook `events` table; a resubmitted copy carries its original's. The event log and the event's page show it in the shared request block, the event log leaving out one over 32 KiB with a link, as for headers. The archive and log targets carry it. HTTP targets gain "Pass the query string on to this target", off by default: on, deliveries, replays and resubmits append it to the target URL, joined with `&` to one already there. The access log still hides it.

Model: opus-5-5

internal/delivery/target_log.go

@@ -9,9 +9,9 @@ import (
 )
 
 // logTarget is a fire-and-forget target that logs the entire
-// inbound webhook — the full request body and headers, plus
-// the method, content type, and the webhook and entrypoint
-// ids — then records a single successful attempt.
+// inbound webhook — the full request body, query string and
+// headers, plus the method, content type, and the webhook and
+// entrypoint ids — then records a single successful attempt.
 //
 // This is the one log call in the service that deliberately writes
 // unbounded client-chosen bytes, so it is the one exception to the
@@ -46,6 +46,7 @@ func (t *logTarget) Deliver(
 		"webhook_id", d.Event.WebhookID,
 		"entrypoint_id", d.Event.EntrypointID,
 		"method", d.Event.Method,
+		"raw_query", d.Event.RawQuery,
 		"content_type", d.Event.ContentType,
 		"headers", d.Event.Headers,
 		"body", d.Event.Body,