docs: Fix DELETE endpoint auth and anonymous users description

- DELETE /services/:fqn uses request body for auth, not query parameters
- Updated anonymous users description to reflect server capabilities
  (not client auto-claiming behavior which was removed)

README.md

@@ -16,7 +16,7 @@ Scalable WebRTC signaling server with cryptographic username claiming, service p
 ## Features
 
 - **Username Claiming**: Cryptographic username ownership with Ed25519 signatures (365-day validity, auto-renewed on use)
-- **Anonymous Users**: Auto-generated anonymous usernames for quick testing without claiming
+- **Anonymous Users**: Support for `anon-*` usernames for quick testing
 - **Service Publishing**: Service:version@username naming (e.g., `chat:1.0.0@alice`)
 - **Service Discovery**: Random and paginated discovery for finding services without knowing usernames
 - **Semantic Versioning**: Compatible version matching (chat:1.0.0 matches any 1.x.x)
@@ -250,10 +250,14 @@ Returns array of unique available offers from different users.
 #### `DELETE /services/:fqn`
 Unpublish a service (requires username, signature, and ownership)
 
-**Query Parameters:**
-- `username` - Your username
-- `signature` - Base64-encoded Ed25519 signature
-- `message` - Signed message (format: `deleteService:{username}:{serviceFqn}:{timestamp}`)
+**Request:**
+```json
+{
+  "username": "alice",
+  "signature": "base64-encoded-signature",
+  "message": "deleteService:alice:chat:1.0.0@alice:1733404800000"
+}
+```
 
 **Response:**
 ```json
@@ -491,8 +495,8 @@ All authenticated requests require:
 
 ### Anonymous Users
 - **Format**: `anon-{timestamp}-{random}` (e.g., `anon-lx2w34-a3f501`)
-- **Generation**: Auto-generated by client for testing
-- **Behavior**: Same as regular usernames, can be claimed
+- **Generation**: Can be generated by client for testing
+- **Behavior**: Same as regular usernames, must be explicitly claimed like any username
 
 ### Service Publishing
 - **Ownership Verification**: Every publish requires username signature