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

cache/cache.go

@@ -6,8 +6,7 @@ import (
 	"sync"
 	"time"
 
-	"github.com/sparetimecoders/goamqp"
-	"gitlab.com/unboundsoftware/eventsourced/eventsourced"
+	"codeberg.org/eventsourced/eventsourced"
 
 	"gitea.unbound.se/unboundsoftware/schemas/domain"
 	"gitea.unbound.se/unboundsoftware/schemas/graph/model"
@@ -133,7 +132,7 @@ func (c *Cache) SubGraphId(orgId, ref, service string) string {
 	return c.subGraphs[subGraphKey(orgId, ref, service)]
 }
 
-func (c *Cache) Update(msg any, _ goamqp.Headers) (any, error) {
+func (c *Cache) Update(msg any) error {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 
@@ -250,7 +249,7 @@ func (c *Cache) Update(msg any, _ goamqp.Headers) (any, error) {
 	default:
 		c.logger.With("msg", msg).Warn("unexpected message received")
 	}
-	return nil, nil
+	return nil
 }
 
 func (c *Cache) updateSubGraph(orgId string, ref string, subGraphId string, service string, updated time.Time) {