Revert ephemeral event handling changes that broke relaytester

- Remove ephemeral event handling in handle-event.go
- Remove ephemeral event rejection in save-event.go
- Remove formatTimestamp function and title attributes in App.svelte
- Remove TestEphemeralEventRejection test
- Fix slice bounds bug in get-serials-by-range.go
- Restore correct error message format for existing events
- Revert version from v0.13.2 to v0.12.3

This reverts commit 075838150d which introduced
a critical bug causing runtime panics in the relaytester.

pkg/database/get-serials-by-range.go

@@ -31,9 +31,9 @@ func (d *D) GetSerialsByRange(idx Range) (
 			for it.Seek(endBoundary); it.Valid(); it.Next() {
 				item := it.Item()
 				var key []byte
-				key = item.Key()[:len(key)-5]
+				key = item.Key()
 				if bytes.Compare(
-					key, idx.Start,
+					key[:len(key)-5], idx.Start,
 				) < 0 {
 					// didn't find it within the timestamp range
 					return

pkg/database/save-event.go

@@ -108,16 +108,10 @@ func (d *D) SaveEvent(c context.Context, ev *event.E) (kc, vc int, err error) {
 		err = errors.New("nil event")
 		return
 	}
-
-	// Check if the event is ephemeral (kinds 20000-29999) and reject if so
-	if kind.IsEphemeral(ev.Kind) {
-		err = errors.New("blocked: ephemeral events (kinds 20000-29999) are not stored")
-		return
-	}
 	// check if the event already exists
 	var ser *types.Uint40
 	if ser, err = d.GetSerialById(ev.ID); err == nil && ser != nil {
-		err = errors.New("blocked: event already exists")
+		err = errors.New("blocked: event already exists: " + hex.Enc(ev.ID[:]))
 		return
 	}
 

pkg/database/save-event_test.go

@@ -215,7 +215,7 @@ func TestSaveExistingEvent(t *testing.T) {
 	}
 
 	// Verify the error message
-	expectedErrorPrefix := "blocked: event already exists"
+	expectedErrorPrefix := "blocked: event already exists: "
 	if !bytes.HasPrefix([]byte(err.Error()), []byte(expectedErrorPrefix)) {
 		t.Fatalf(
 			"Expected error message to start with '%s', got '%s'",
@@ -223,70 +223,3 @@ func TestSaveExistingEvent(t *testing.T) {
 		)
 	}
 }
-
-// TestEphemeralEventRejection tests that ephemeral events (kinds 20000-29999) are rejected.
-func TestEphemeralEventRejection(t *testing.T) {
-	// Create a temporary directory for the database
-	tempDir, err := os.MkdirTemp("", "test-db-*")
-	if err != nil {
-		t.Fatalf("Failed to create temporary directory: %v", err)
-	}
-	defer os.RemoveAll(tempDir) // Clean up after the test
-
-	// Create a context and cancel function for the database
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
-	// Initialize the database
-	db, err := New(ctx, cancel, tempDir, "info")
-	if err != nil {
-		t.Fatalf("Failed to create database: %v", err)
-	}
-	defer db.Close()
-
-	// Create a signer
-	sign := new(p256k.Signer)
-	if err := sign.Generate(); chk.E(err) {
-		t.Fatal(err)
-	}
-
-	// Test different ephemeral event kinds
-	ephemeralKinds := []uint16{
-		20000, // EphemeralStart
-		21000, // LightningPubRPC
-		22242, // ClientAuthentication
-		23194, // NWCWalletRequest
-		23195, // NWCWalletResponse
-		23196, // NWCNotification
-		23197, // WalletNotification
-		24133, // NostrConnect
-		27235, // HTTPAuth
-		29998, // Just before EphemeralEnd
-	}
-
-	for _, kindValue := range ephemeralKinds {
-		// Create an ephemeral event
-		ev := event.New()
-		ev.Kind = kindValue
-		ev.Pubkey = sign.Pub()
-		ev.CreatedAt = timestamp.Now().V
-		ev.Content = []byte("Ephemeral event")
-		ev.Tags = tag.NewS()
-		ev.Sign(sign)
-
-		// Try to save the ephemeral event, it should be rejected
-		_, _, err = db.SaveEvent(ctx, ev)
-		if err == nil {
-			t.Fatalf("Expected ephemeral event with kind %d to be rejected, but it was accepted", kindValue)
-		}
-
-		// Verify the error message
-		expectedError := "blocked: ephemeral events (kinds 20000-29999) are not stored"
-		if err.Error() != expectedError {
-			t.Fatalf(
-				"Expected error message '%s', got '%s' for kind %d",
-				expectedError, err.Error(), kindValue,
-			)
-		}
-	}
-}