feat: add gqlgen Recover that logs panics as one structured record

gqlgen's DefaultRecover prints the panic and debug.PrintStack() to stderr, so the log collector stores every stack line as a separate, level-less entry. Recover logs the panic as a single ERROR record via slog.Default() with panic, stack and path attributes, records it on the active span with status Error, and returns the generic "internal system error" without leaking the panic text. Install with srv.SetRecoverFunc(otelsetup.Recover).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01H6eVuR4Yt3m7TbDTDwyZJi

go.mod

@@ -6,6 +6,7 @@ require (
 	codeberg.org/eventsourced/eventsourced v1.24.0
 	codeberg.org/eventsourced/pg/v2 v2.3.0
 	github.com/99designs/gqlgen v0.17.95
+	github.com/vektah/gqlparser/v2 v2.5.37
 	go.opentelemetry.io/otel v1.47.0
 	go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp v1.47.0
 	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.47.0
@@ -30,7 +31,6 @@ require (
 	github.com/pressly/goose/v3 v3.28.0 // indirect
 	github.com/sethvargo/go-retry v0.4.0 // indirect
 	github.com/sosodev/duration v1.4.0 // indirect
-	github.com/vektah/gqlparser/v2 v2.5.37 // indirect
 	go.opentelemetry.io/auto/sdk v1.2.1 // indirect
 	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.47.0 // indirect
 	go.opentelemetry.io/otel/log v1.47.0 // indirect