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.

go.mod

@@ -1,6 +1,6 @@
 module next.orly.dev
 
-go 1.25.0
+go 1.25.3
 
 require (
 	github.com/adrg/xdg v0.5.3
@@ -22,7 +22,7 @@ require (
 	honnef.co/go/tools v0.6.1
 	lol.mleku.dev v1.0.5
 	lukechampine.com/frand v1.5.1
-	p256k1.mleku.dev v1.0.3
+	p8k.mleku.dev v1.0.0
 )
 
 require (
@@ -30,6 +30,7 @@ require (
 	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/dgraph-io/ristretto/v2 v2.3.0 // indirect
 	github.com/dustin/go-humanize v1.0.1 // indirect
+	github.com/ebitengine/purego v0.9.1 // indirect
 	github.com/felixge/fgprof v0.9.5 // indirect
 	github.com/go-logr/logr v1.4.3 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect