Refactor signer implementation to use p8k package

- Replaced all instances of p256k1signer with the new p8k.Signer across various modules, including event creation, policy handling, and database interactions.
- Updated related test cases and benchmarks to ensure compatibility with the new signer interface.
- Bumped version to v0.25.0 to reflect these significant changes and improvements in cryptographic operations.

pkg/crypto/encryption/benchmark_test.go

@@ -3,7 +3,7 @@ package encryption
 import (
 	"testing"
 
-	p256k1signer "p256k1.mleku.dev/signer"
+	"next.orly.dev/pkg/interfaces/signer/p8k"
 	"lukechampine.com/frand"
 )
 
@@ -13,8 +13,8 @@ func createTestConversationKey() []byte {
 }
 
 // createTestKeyPair creates a key pair for ECDH testing
-func createTestKeyPair() (*p256k1signer.P256K1Signer, []byte) {
-	signer := p256k1signer.NewP256K1Signer()
+func createTestKeyPair() (*p8k.Signer, []byte) {
+	signer := p8k.MustNew()
 	if err := signer.Generate(); err != nil {
 		panic(err)
 	}