refactor: use AuthStore interface and remove type assertions

Replace runtime type assertions with compile-time safe AuthStore interface.
Add connState struct for cleaner per-connection state management instead
of mutable pointer parameters. Reduce auth challenge TTL from 10min to 2min.

- Add AuthStore interface with CreateAuthChallenge and ValidateAndConsumeChallenge
- Add connState struct for authenticatedPubkey and authChallenge
- Remove fragile type assertion pattern in requireAuth and handleAuth
- Add nil checks for auth store with clear error messages
- Update Handler to have separate auth field
- Wire auth store in main.go when auth is enabled

1 files changed, 1 insertions, 0 deletions

diff --git a/cmd/relay/main.go b/cmd/relay/main.go
index 6974f65..e4afec8 100644
--- a/cmd/relay/main.go
+++ b/cmd/relay/main.go
@@ -116,6 +116,7 @@ func main() {
         }
 
         if cfg.Auth.Read.Enabled || cfg.Auth.Write.Enabled {
+                wsHandler.SetAuth(store)
                 wsHandler.SetAuthConfig(&wshandler.AuthConfig{
                         ReadEnabled:         cfg.Auth.Read.Enabled,
                         WriteEnabled:        cfg.Auth.Write.Enabled,