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

The receiver keeps the query string of the request it received on the event, 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 with the request, the event log leaving out one over 32 KiB as it does request headers. The archive and log targets carry it. An HTTP target gets a `forwardQuery` setting, off by default, on both target forms and in the target list: on, each delivery, replays and resubmits included, appends the query string to the target URL, joined with `&` to one it already has.

Model: opus-5-5

internal/handlers/target_create.go

@@ -173,6 +173,9 @@ type targetFormInput struct {
 	Headers string
 	// Timeout is an HTTP target's per-request timeout in seconds.
 	Timeout string
+	// ForwardQuery is an HTTP target's checkbox that passes each
+	// event's query string on to it.
+	ForwardQuery bool
 	// MaxRetries is an HTTP or Slack target's max_retries.
 	MaxRetries string
 	// Expiry is a database (archive) target's row expiry.
@@ -195,14 +198,15 @@ type targetFormInput struct {
 // tokens.
 func targetFormInputFrom(r *http.Request) targetFormInput {
 	return targetFormInput{
-		Name:       r.PostFormValue("name"),
-		Type:       database.TargetType(r.PostFormValue("type")),
-		URL:        r.PostFormValue("url"),
-		Headers:    r.PostFormValue("headers"),
-		Timeout:    r.PostFormValue("timeout"),
-		MaxRetries: r.PostFormValue("max_retries"),
-		Expiry:     r.PostFormValue("expiry"),
-		Rotation:   r.PostFormValue("rotation"),
+		Name:         r.PostFormValue("name"),
+		Type:         database.TargetType(r.PostFormValue("type")),
+		URL:          r.PostFormValue("url"),
+		Headers:      r.PostFormValue("headers"),
+		Timeout:      r.PostFormValue("timeout"),
+		ForwardQuery: r.PostFormValue("forward_query") != "",
+		MaxRetries:   r.PostFormValue("max_retries"),
+		Expiry:       r.PostFormValue("expiry"),
+		Rotation:     r.PostFormValue("rotation"),
 	}
 }
 
@@ -232,8 +236,8 @@ func (h *Handlers) buildTargetConfig(
 }
 
 // buildHTTPTargetConfig builds config JSON for an HTTP target: an
-// SSRF-validated destination plus the optional headers and timeout
-// the delivery path honours.
+// SSRF-validated destination plus the optional headers, timeout and
+// query string setting the delivery path honours.
 func (h *Handlers) buildHTTPTargetConfig(
 	ctx context.Context,
 	in targetFormInput,
@@ -256,9 +260,10 @@ func (h *Handlers) buildHTTPTargetConfig(
 	}
 
 	configJSON, err := marshalTargetConfig(delivery.HTTPTargetConfig{
-		URL:     in.URL,
-		Headers: headers,
-		Timeout: timeout,
+		URL:          in.URL,
+		Headers:      headers,
+		Timeout:      timeout,
+		ForwardQuery: in.ForwardQuery,
 	})
 
 	return configJSON, "", err