feat: add Connect (gRPC over HTTP/JSON) support

Connect integration:
- Buf Connect codegen added to buf.gen.yaml
- Connect handler wraps gRPC server
- Serves on same port as WebSocket (:8080)
- HTTP/2 with h2c for cleartext HTTP/2

Now serving THREE protocols:
1. gRPC (native) on :50051 - binary, high performance
2. Connect on :8080/nostr.v1.NostrRelay/* - HTTP/JSON, browser compatible
3. WebSocket on :8080/ - Nostr standard protocol

All three protocols share:
- Same storage layer
- Same subscription manager
- Same validation logic

Browser-friendly! Call gRPC methods with fetch() or curl.

1 files changed, 4 insertions, 3 deletions

diff --git a/go.mod b/go.mod
index 03667f7..a291cec 100644
--- a/go.mod
+++ b/go.mod
@@ -11,6 +11,7 @@ require (
 )
 
 require (
+        connectrpc.com/connect v1.19.1 // indirect
         github.com/btcsuite/btcd/chaincfg/chainhash v1.0.1 // indirect
         github.com/decred/dcrd/crypto/blake256 v1.0.0 // indirect
         github.com/decred/dcrd/dcrec/secp256k1/v4 v4.0.1 // indirect
@@ -20,9 +21,9 @@ require (
         github.com/ncruces/go-strftime v1.0.0 // indirect
         github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec // indirect
         golang.org/x/exp v0.0.0-20251023183803-a4bb9ffd2546 // indirect
-        golang.org/x/net v0.48.0 // indirect
-        golang.org/x/sys v0.39.0 // indirect
-        golang.org/x/text v0.32.0 // indirect
+        golang.org/x/net v0.50.0 // indirect
+        golang.org/x/sys v0.41.0 // indirect
+        golang.org/x/text v0.34.0 // indirect
         google.golang.org/genproto/googleapis/rpc v0.0.0-20251202230838-ff82c1b0f217 // indirect
         modernc.org/libc v1.67.6 // indirect
         modernc.org/mathutil v1.7.1 // indirect