Add NWC protocol handling and NIP-44 encryption and decryption functions.

pkg/protocol/nwc/README.md

@@ -0,0 +1,56 @@
+# NWC Client
+
+Nostr Wallet Connect (NIP-47) client implementation.
+
+## Usage
+
+```go
+import "orly.dev/pkg/protocol/nwc"
+
+// Create client from NWC connection URI
+client, err := nwc.NewClient("nostr+walletconnect://...")
+if err != nil {
+    log.Fatal(err)
+}
+
+// Make requests
+var info map[string]any
+err = client.Request(ctx, "get_info", nil, &info)
+
+var balance map[string]any
+err = client.Request(ctx, "get_balance", nil, &balance)
+
+var invoice map[string]any
+params := map[string]any{"amount": 1000, "description": "test"}
+err = client.Request(ctx, "make_invoice", params, &invoice)
+```
+
+## Methods
+
+- `get_info` - Get wallet info
+- `get_balance` - Get wallet balance  
+- `make_invoice` - Create invoice
+- `lookup_invoice` - Check invoice status
+- `pay_invoice` - Pay invoice
+
+## Payment Notifications
+
+```go
+// Subscribe to payment notifications
+err = client.SubscribeNotifications(ctx, func(notificationType string, notification map[string]any) error {
+    if notificationType == "payment_received" {
+        amount := notification["amount"].(float64)
+        description := notification["description"].(string)
+        // Process payment...
+    }
+    return nil
+})
+```
+
+## Features
+
+- NIP-44 encryption
+- Event signing
+- Relay communication
+- Payment notifications
+- Error handling