Refactor for interface clarity and dependency isolation.

Replaced inline interface literals with dedicated, documented interface definitions in `pkg/interfaces/`. Introduced `TimeoutError`, `PolicyChecker`, and `Neo4jResultIterator` interfaces to clarify design, improve maintainability, and resolve potential circular dependencies. Updated config and constant usage rules for consistency. Incremented version to v0.31.11.

pkg/interfaces/acl/acl.go

@@ -2,6 +2,7 @@
 package acl
 
 import (
+	"git.mleku.dev/mleku/nostr/encoders/event"
 	"next.orly.dev/pkg/interfaces/typer"
 )
 
@@ -31,3 +32,9 @@ type I interface {
 	Syncer()
 	typer.T
 }
+
+// PolicyChecker is an optional interface that ACL implementations can implement
+// to provide custom event policy checking beyond basic access level checks.
+type PolicyChecker interface {
+	CheckPolicy(ev *event.E) (allowed bool, err error)
+}