refactor: migrate eventsourced to codeberg and go-messaging-amqp

Move eventsourced modules from gitlab.com/unboundsoftware to codeberg.org/eventsourced.
The Codeberg amqp publisher is built on go-messaging-amqp, so the service
switches from sparetimecoders/goamqp as well:

- routing keys are mapped on the eventsourced publisher (newEventPublisher)
- cache consumers are typed handlers; Cache.Update drops the goamqp shape
- publishes detach from the request context (uncancelledPublisher)
- closeEvents is buffered and the receiver also watches rootCtx
- WithPrefetchLimit dropped (no-op, 20 is the default)
- amqp091-go v1.15.0 (GO-2026-6372)
- renovate groups codeberg.org/messaging with eventsourced

Only transient consumer queues are used, so no queue cutover is needed.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Dpb7Y47dPz246oY9bCzh7k

graph/resolver.go

@@ -5,7 +5,7 @@ import (
 	"fmt"
 	"log/slog"
 
-	"gitlab.com/unboundsoftware/eventsourced/eventsourced"
+	"codeberg.org/eventsourced/eventsourced"
 
 	"gitea.unbound.se/unboundsoftware/schemas/cache"
 	"gitea.unbound.se/unboundsoftware/schemas/graph/model"

graph/schema.helpers.go

@@ -3,7 +3,7 @@ package graph
 import (
 	"context"
 
-	"gitlab.com/unboundsoftware/eventsourced/eventsourced"
+	"codeberg.org/eventsourced/eventsourced"
 
 	"gitea.unbound.se/unboundsoftware/schemas/domain"
 	"gitea.unbound.se/unboundsoftware/schemas/graph/model"

graph/schema.resolvers.go

@@ -10,7 +10,7 @@ import (
 	"fmt"
 	"strings"
 
-	"gitlab.com/unboundsoftware/eventsourced/eventsourced"
+	"codeberg.org/eventsourced/eventsourced"
 
 	"gitea.unbound.se/unboundsoftware/schemas/domain"
 	"gitea.unbound.se/unboundsoftware/schemas/graph/generated"